mydos 4.3a user guide · icd p:r:connection serial/parallel interface axlon rampower 128 plus ram...
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MY
DO
S
Ve
rs
ion
4
U
se
r
Gu
ide
R
ev
isio
n
4.
3A fo
r
Ata
ri
Ho
rne
C
om
pu
ter
s
Ch
ar
les
W.
Ma
rs
lett
WO
RD
MA
RK
S
ys
tem
s
27
05
P
ine
woo
d
Dr
. G
ar
lan
d,
TX
750
42
Oc
tob
er
21,
1986
Th
ie
info
rm
atio
n
is
dis
clo
se
d
for
th
e
pe
rs
on
al,
pr
iva
te
us
e
of
cu
sto
me
rs
o
f W
OR
DM
AR
K
Sy
ste
ms
a
nd
th
eir
e
mp
loy
ee
s.
WO
RD
MA
RK
S
ys
tem
s
re
se
rv
es
th
e
rig
ht
to
m
ak
e
ch
an
ge
s
to
th
is
do
cu
me
nt
an
d
to
the
p
ro
du
ct
de
sc
rib
ed
a
t
an
y
time
w
itho
ut
fur
the
r
no
tice
. T
he
in
for
ma
tion
in
th
is
do
cu
me
nt
is
be
liev
ed
lo
b
e
acc
ur
ate
a
nd
r
elia
ble
. H
ow
ev
e1·,
no
re
sp
on
sib
ility
is
as
su
me
d
by
W
OR
DM
AR
K
Sy
ste
ms
fo
r
its
us
e;
no
r
an
y
infr
ing
em
en
ts
to
c
op
yr
igh
ts,
pa
ten
ts
or
r
igh
ts
of
a
ny
th
ird
p
ar
ties
r
es
ultin
g
fro
m
its
us
e.
MYDOS
Hard
ware
Coa
pati
bity
Th
e
MY
DO
S
3
an
d
4
Dis
k
Op
er
atin
g
Sy
ste
ms
a
re
in
ten
de
d
to
wo
rk
w
ith
as
m
an
y
diffe
re
nt
ha
rd
wa
re
c
on
figu
ra
tion
s
as
p
os
sib
le:
eith
er
11
18Y
be
u
se
d
with
a
ny
A
tar
i 8
b
it c
om
pu
ter
fr
om
th
e o
lde
st
400
a
nd
8
00
mo
de
ls
(with
th
e
A
Re
vis
ion
O
S
RO
Ms
) to
th
e
cu
rr
en
t 6
5X
E
an
d
13
0X
E
mo
de
ls,
I h
av
e
ve
rifie
d
tha
t th
e
follo
win
g
pe
rp
he
ra
l h
ar
dw
ar
e
wo
rk
s
with
b
oth
m
ajo
r
ve
rs
ion
s
of
MY
DO
S:
Ata
ri
81
0
Dis
k
Dr
ive
A
tar
i 8
10
D
isk
D
riv
e
with
Hap
py
up
gr
ad
e
Ata
ri
10
50
D
isk
D
riv
e
in
sin
gle
de
ns
ity
mod
e
Pe
rc
om
R
FD
se
rie
s
Dis
k
Dr
ive
s
SW
P
Mic
roc
om
pu
ter
P
ro
du
cts
A
TR
800
0 S
WP
M
icr
oco
mp
ute
r
Pr
od
uc
ts
AT
R8
50
0
Ind
us
G
T
Dis
k
Dr
ive
(8
50
a
nd
P
er
co
m
co
mp
atib
le
mod
es
) Z
-T
ec
H
ar
d
Dis
k
Inte
rfa
ce
a
nd
D
riv
e
Ata
ri
85
0
se
ria
l/p
ar
alle
l in
ter
face
IC
D
P:R
:Co
nn
ec
tion
s
er
ial/
par
alle
l in
ter
fac
e
Ax
lon
RA
MP
ow
er
12
8
Plu
s
RAM
u
pg
ra
de
fo
r
the
800
ICD
Ra
mbo
X
L
25
6K
RA
M
up
gr
ad
e
for
th
e
80
0X
L
Ne
we
ll In
du
str
ies
2
56
K
RAM
Up
gr
ad
e
for
th
e
800
XL
M
ag
na
S
ys
tem
s
51
2K
RA
M
Up
gr
ad
e
for
th
e
80
0
Th
e
follo
win
g
ha
rd
wa
re
h
as
b
ee
n r
epo
rte
d to
w
or
k
pr
ope
rly
w
ith
MY
DO
S:
Ata
ri
10
50
d
isk
d
riv
es
wi
th
the
IC
D
US
Dou
ble
r
As
tra
B
ig
D
(du
al
do
ub
le
sid
ed
d
isk
d
riv
e)
As
tra
2
000
(du
al
sin
gle
s
ide
d
dis
k
dr
ive
) A
md
ek
3
1
/2
" s
ys
tem
s
(with
a
nd
w
itho
ut
5
1/4
" d
riv
es
) In
du
s
GT
D
isk
D
riv
e
(with
n
ew
R
OM
) in
all d
en
sitie
s
Su
pr
a
Co
rp
. W
inc
he
ste
r
dis
k
inte
rfa
ce
s
an
d
sy
ste
m•
S
WP
M
icr
oco
mp
ute
r
Sy
ste
ms
Ha
rd
D
isk
S
ub
sy
ste
m
Th
e
follo
win
g
ha
rd
wa
re
o
r
mo
dific
atio
ns
a
re
r
epo
rte
d
to
no
t w
or
k
pr
op
er
ly
with
M
YD
OS
3
a
nd
MY
DO
S 4
:
Ba
sic
/X
E
with
th
e
Ne
we
ll 2
56
K
Up
gr
ad
e
(pr
ior
to
4.2
) B
as
ic/
XE
w
ith
the
IC
D
Ram
bo 2
56
K
Up
gr
ad
e
(pr
ior
to
4.3
) S
om
e
Ind
us
G
T
dis
k d
riv
es
(p
er
ha
ps
e
ar
ly o
ne
s)
do
n
ot
pr
op
er
ly r
ec
og
niz
e
dis
ke
tte d
en
sitie
s
So
me
P
er
co
m
dis
k
dr
ive
s
(pr
ob
ab
ly
the
n
1>w
es
t o
ne
s)
do
no
t p
ro
per
ly r
ec
og
niz
e
dis
ke
tte
de
ns
ities
T
he
o
rig
ina
l p
ub
lic
do
ma
in
25
6K
RA
M
up
gr
ad
e
(sin
ce
it
us
es
a
3
2K
p
ag
e
siz
e)
is
inc
om
pa
tible
w
ith
the
M
YD
OS
R
AM
dis
k
co
de
M
an
y
me
nu
p
ro
gr
am
s
an
d
pr
og
ra
ms
w
ith
ov
er
lay
s
tha
t e
xe
cu
te
su
br
ou
tine
s
with
in
DO
S
2.0
, D
OS
2
.5
or
S
pa
rta
DO
S,
Su
mmar
y
of c
ha
ng
es
: M
YDOS
R
ele
as
e
4.3
A
Oc
tob
er
2
3,
198
6
Th
is
re
lea
se
o
f M
YD
OS
, d
ate
d
Oc
tob
er
2
1, 19
86
, a
dd
s
two
n
ew
c
om
ma
nd
s
C'S'
to
se
t th
e
RA
Md
isk
d
riv
e
nu
mb
er
a
nd
'V'
to
tur
n
on
a
nd
o
ff W
rite
-V
er
ify).
It a
lso
c
or
re
cts
a
lo
ng
s
tan
din
g
pr
ob
lem
th
at
occ
ur
s
if a
d
ire
cto
ry
is
d
ele
ted
an
d
inc
lud
es
n
ew
c
od
e
to
cy
cle
th
ro
ug
h
all
ac
tive
d
riv
es
loo
kin
g
for
D
UP
.SY
S.
MY
DO
S
4.3
c
or
re
cted
tw
o
pr
ob
lem
s
in
the
e
rr
or
h
an
dlin
g
co
de
p
re
se
nt
in
ea
rlie
r
ve
rs
ion
s
an
d
ha
d
imp
ro
ve
d
ma
nu
al
co
ve
ra
ge
fo
r
se
ve
ra
l n
ew
er
fe
atu
re
s.
Th
e
ne
w
co
mm
an
ds
a
re
s
ub
se
ts
of
the
'O
' c
om
ma
nd
p
er
mittin
g
the
m
os
t c
om
mo
n
ch
an
ge
s
to
be
m
ad
e
with
ou
t r
ec
on
figu
rin
g
the
e
ntir
e
sy
ste
m.
Th
e
er
ro
r
in
the
d
ele
te
co
de
fo
r
dir
ec
tor
ies
c
au
se
d
the
b
oot
se
cto
rs
a
nd
th
e
firs
t file
o
n
the
d
isk
to
b
e
dis
tro
ye
d
wh
en
th
e
firs
t file
w
as
w
ritte
n
to
the
d
isk
a
fter
a
d
ire
cto
ry
h
ad
b
ee
n
de
lete
d
(the
V
TO
C
fre
e
se
cto
r
bit
ma
p
wa
s
inc
or
re
ctly
u
pd
ate
d w
he
n
the
dir
ec
tor
y w
as
d
ele
ted
).
Th
e
or
igin
al
co
de
to
lo
ad
D
UP
.SY
S
ign
or
ed
e
rr
or
s,
no
w
it c
yc
les
to
th
e
ne
xt
va
lid
dr
ive
o
n
the
s
ys
tem
if
a
va
lid
DU
P.S
YS
is
n
ot
fou
nd
. U
ntil
the
C
RC
/c
he
ck
su
m
co
de
is
a
dd
ed
n
ex
t y
ea
r,
this
w
ill c
au
se
r
ea
l c
on
fus
ion
if
dis
ks
w
ith
diffe
re
nt
ve
rs
ion
s
of
MY
DO
S
(or
A
tar
i D
OS
) a
re
in
u
se
a
t o
ne
tim
e.
Th
is
pe
rm
its
DU
P.S
YS
to
b
e
loa
de
d fr
om
a
fio
pp
y
if th
e
DU
P.S
YS
o
n
the
h
ar
d
dis
k
or
R
AM
dis
k
is
ina
dv
er
ten
tly
de
lete
d
an
d
yo
u
the
n
atte
mp
t to
g
o
to
MY
DO
S
fro
m
BA
SIC
o
r
wh
ate
ve
r.
Th
e
doc
um
en
tation
h
as
b
ee
n
ex
ten
de
d
to
co
ve
r
RA
Md
isk
u
sa
ge
a
nd
in
co
rr
ec
t in
for
ma
tion
in
th
e
er
ro
r
de
sc
rip
tion
s
an
d
co
nfig
ur
atio
n
co
mm
an
d
de
sc
rip
tion
s
ha
ve
b
ee
n c
or
re
cte
d.
A
sh
or
t ch
ap
ter
h
as
b
ee
n
ad
de
d
to
co
ve
r
the
o
pe
ra
tion
o
f th
e
RA
Md
isk
d
riv
er
-
-N
ow
th
e
sh
or
t R
AM
dis
k
se
qu
en
ce
s
su
pp
or
ted
a
re
:
0
An
Ata
ri
130
XE
o
r
co
mp
atib
le
RA
Md
isk
w
itho
ut
BA
SIC
/X
E o
r
oth
er
XE
p
ro
gr
am
s
An
Ata
ri
130
XE
c
om
patib
le
with
19
ZK
fo
r
the
R
AM
dis
k,
the
la
st
64K
o
f w
hic
h
ma
y
be
u
se
d
by
B
AS
IC/
XE
, u
sin
g th
e
Ne
we
ll In
du
str
ies
m
em
or
y m
ap
2
-
An
A
tari
13
0X
E
co
mp
at
ible
w
ith
1
92
K f
or
t
he
RAM
dis
k,
us
ing
th
e
JC
D
me
mor
y ma
p
(ne
w)
in
4.3
A t
his
is n
ow
BA
SI
C/
XE
c
om
pat
ible
(a
1
28
K RAM
dis
k
an
d
64
K fo
r
BA
SI
C/
XE
)
5
--
An
Ax
ion
c
om
pa
tible
RAM
dis
k
of
at
lea
st 4
0K
Th
e
ne
xt
re
lea
se
(p
ro
ba
bly
in
th
e
sp
rin
g
of
198
7)
will
ad
d
a
CR
C
ch
ec
k
on
r
es
ide
nt
co
de
to
g
ua
rd
a
ga
ins
t e
rr
or
s
tha
t m
igh
t oc
cu
r
afte
r
pa
rt
of
the
r
es
ide
nt
co
de
is
d
istr
oy
ed
. It
will
als
o
inc
lud
e
pe
rm
an
en
t d
riv
er
s
for
th
e
Ata
ri
85
0
an
d
!CD
's
P:R
:Co
nn
ec
tion
. I
ma
y
be
a
ble
to
a
dd
s
up
por
t fo
r
the
A
tar
i 10
30
a
nd
D
OS
Z.5
's
ex
ten
de
d
file
sy
ste
m
(an
d
I m
ay
n
ot!).
Ch
ar
les
M
ar
sle
tt
I.
I
NT
RO
DU
CT
IO
N
II
I.
S
YS
TE
M
RE
QU
IR
EM
EN
TS
II
I.
ME
NU
FU
NC
TI
ON
S
IV
.
TH
E
ME
NU
C
OM
MA
ND
S
A.
L
is
t
a
Di
re
ct
or
y o
r
a
Se
t
of
Fi
le
s
B.
R
un
t
he
C
ar
tr
id
ge
C
.
Co
py
a F
il
e
or
a
Se
t
of
F
le
s
D.
D
el
et
e
a
Fi
le
o
r
Se
t
of
F
le
s E
. R
en
am
e
a
Fi
le
o
r
Se
t
of
F
l
es
F
. L
oc
k a
F
il
e
or
S
et
of
Fi
le
s
G.
U
nl
oc
k
a
Fi
le
o
r
Se
t
of
Fi
le
s
H.
Wr
it
e M
YD
OS
4
to
a
D
is
k
I.
I
ni
ti
al
iz
e
a
Di
sk
et
te
J
. D
up
li
ca
te
a
D
is
ke
tt
e
K.
S
av
e M
em
or
y t
o
Di
sk
L
.
Lo
ad
Me
mo
ry
fr
om
a
Fi
le
M
.
Ru
n
at
A
dd
re
ss
N
. L
oa
d
ME
M.
SAV
f
rom
a
Fi
le
0
. S
ys
te
m
an
d
Dr
iv
e
Co
nf
ig
ur
at
io
n
P.
D
is
ke
tt
e
De
ns
it
y S
el
ec
ti
on
Q
. C
re
at
e
Ad
di
ti
on
al
Di
re
ct
or
ie
s
R.
S
et
t
he
D
ef
au
lt
D
ir
ec
to
ry
S.
·se
t
th
e
RA
Md
is
k D
ri
ve
Nu
mb
er
V
. S
et
Wr
it
e
Ve
ri
fy
ON
o
r
OFF
V
. F
IL
E
MA
NA
GE
R
FU
NC
TI
ON
S
PR
OV
ID
ED
T
HR
OU
Gll
CI
O V
I.
C
IO
F
UN
CT
IO
N
CO
DE
S
PR
OV
ID
ED
BY
M
YD
OS
4
Fu
nc
ti
on
c
od
e 3
, O
PE
N
Fu
nc
ti
on
c
od
e
5,
G
ET
R
EC
OR
D
Fu
nc
ti
on
c
od
e
7,
G
ET
C
HA
RA
CT
ER
S
Fu
ne
ti o
n
co
de
9,
PU
T
RE
CO
RD
F
un
ct
io
n
co
de
11
, P
UT
C
llAR
AC
TE
RS
F
un
ct
io
n
co
de
12
, C
LO
SE
A
FI
LE
F
un
ct
io
n
co
de
13
, R
EA
D
ST
AT
US
F
un
ct
io
n
co
de
3
2,
RE
NA
ME
A
FI
LE
F
un
ct
io
n
co
de
33
, D
EL
ET
E
A F
IL
E F
un
ct
io
n
co
de
3
4,
MA
KE
D
IR
EC
TO
RY
F
un
ct
io
n
co
de
35
,
LO
CK
FI
LE
F
un
ct
io
n
co
de
36
,
UN
LO
CK
FI
LE
Fu
nc
ti
on
c
od
e 3
7,
PO
IN
T
TO
P
OS
IT
IO
N
IN
F
IL
E F
un
ct
io
n
co
de
3
8,
NO
TE
P
OS
IT
IO
N
IN
FI
LE
F
un
ct
io
n
co
de
39
, L
OA
D M
EM
OR
Y
Fu
nc
ti
on
c
od
e
41
, S
ET
D
EFA
UL
T
DI
RE
CT
OR
Y
Fu
nc
ti
on
c
od
e
25
4,
FO
RM
AT
A
D
IS
KE
TT
E
VI
I.
DI
SK
S
TR
UC
TU
RE
S
SU
PP
OR
TI
NG
MY
DO
S
4 V
II
I.
MY
DO
S
4 M
EM
OR
Y
MA
P
IX
.
CU
ST
OM
IZ
IN
G
A
SY
ST
EM
DI
SK
C
us
to
m
RA
Md
is
k
Co
nfi
gu
ra
ti
on
s N
umb
er
o
f F
il
es
O
pe
n a
t
On
ce
C
on
tr
ol
li
ng
t
he
D
is
k D
ri
ve
s
Ac
ce
ss
ed
by
M
YD
OS
4
Se
le
ct
in
g
or
D
is
ab
li
ng
Wr
it
e-
wi
th
-V
er
if
y
X.
D
IS
K
DR
IV
E
IN
TE
RF
AC
E
<vi
a S
IO
l X
I.
R
AM
DI
SK
I
NT
ER
FA
CE
X
II
. I
NI
TI
AL
I
NS
TA
LL
AT
ION
I
NS
TR
UC
TI
ON
S
XI
I.
E
RR
OR
C
OD
ES
A
ND
T
HE
IR
S
OU
RC
ES
2 2
3
5 5 6 6 7 7 7 8 8 9 9
10
1
0
11
11
1
1
13
14
1
5 1
5 1
5
15
17
1
7
18
18 1
8 1
9 19 1
9 19
2
0 2
0 2
0 21
2
1
21
22
22
2
2
23
2
3
24
2
4 2
5
26
26
2
7
29
3
0
33
MY
DO
S
Ve
rs
io
n.
4
Us
er
G
�i
de
by
C
ha
rles W
. M
arsle
tt
I. IN
TR
OD
UC
TIO
N
Th
e
dis
k o
pe
ratin
g
sy
ste
m
de
sc
ribed
in
this
ma
nu
al
is
mo
de
led
afte
r th
e
AT
AR
I (tr
ad
em
ar
k
of A
TA
RI
Co
rp.) d
isk
o
pe
ratin
g
sy
ste
ms
(D
OS
a
nd
D
OS
2)
an
d
ma
y
be
c
on
side
re
d
an
e
xten
sion
o
f th
e
ve
ry
"user
frie
nd
ly"
co
nc
ep
ts in
tro
du
ce
d
with
th
ose
tw
o
op
era
ting
s
yste
ms
. T
he
AT
AR
I 8
10
dis
k
driv
e
an
d
the
A
TA
RI
105
0
disk
d
rive
ar
e
we
ll s
up
po
rted
b
y
the
D
OS
2
an
d
DO
S
2.5 o
pe
ratin
g
sy
ste
ms
, b
ut
tho
se
DO
Ss
ha
ve
v
ery
lim
ited
p
rov
ision
fo
r h
igh
er
ca
pa
city
d
ou
ble
de
nsity
d
isk
s.
II. S
YS
TE
M
RE
QU
IRE
ME
NT
S
MY
DO
S
4.3
is
inte
nd
ed
to
fu
nc
tion
a
s n
ea
rly
as
po
ssible
lik
e
AT
AR
I D
OS
2.
Th
is
me
an
s it o
cc
up
ies
as
little
me
mo
ry
as
po
ssible
, su
pp
orts a
ll th
e
sy
stem
c
alls
sup
po
rted
b
y
DO
S
2
an
d
in
mo
st c
ase
s, u
ses
ex
ac
tly
the
sa
me
p
ara
me
ter
s
to
the
s
yste
m ca
lls. M
ost
pro
gra
ms
tha
t c
an
b
e
cop
ied
to
a
sta
nd
ar
d
AT
AR
I D
OS
2
dis
k a
nd
ru
n
from
th
at
dis
k
ca
n a
lso
be
r
un
fr
om
a
ny
M
YD
OS
d
isk
. T
he
la
rge
st g
ro
up
s
of
pro
gra
ms
tha
t d
o
no
t w
or
k
this
wa
y
are
tho
se
th
at
acc
es
s
the
d
isk
th
ro
ug
h
calls
to
en
try
p
oin
ts
ins
ide
th
e
DO
S
file m
an
ag
er
or
"FM
S".
Pr
og
ra
ms
th
at
de
pe
nd
o
n
an
e
xa
ct
scre
en
m
en
u
or
a
pr
ecise fo
rma
t fo
r th
e
dir
ecto
ry
d
ata
w
ill a
lso
ha
ve
d
ifficu
lty
ru
nn
ing
p
rop
erly
-
-o
ne
co
mm
on
p
rob
lem
is
for
pro
gra
ms
to
ex
pe
ct
ex
ac
tly
3 d
igits
in
the
file size
field
a
nd
th
e
free se
cto
rs fie
ld
of d
ire
cto
ries
.
Th
e
ha
rdw
are
n
ee
de
d
to
ru
n
MY
DO
S
4.3
c
on
sists o
f a
t le
ast
on
e
AT
AR
I D
OS
2
com
pa
tible
d
isk
d
rive
o
r e
qu
iva
len
t a
nd
a
n
AT
AR
I 8
-b
it co
mp
ute
r (40
0,
80
0,
120
0X
L,
60
0X
L,
80
0X
L,
1450
XL
D,
65X
E
or
13
0X
E).
MY
DO
S
4 is
n
ot
com
pa
tible
w
ith
the
A
TA
RI
16-
bit
co
mp
ute
rs
. M
YD
OS
4
do
es
n
ot
sup
po
rt th
e
DO
S
2.5
e
nh
an
ce
d
de
nsity
fo
rma
t, th
e
DO
S/
XL
V
er
sion
4
form
at o
r th
e S
pa
rtaD
OS
fo
rma
t, eith
er.
In
ad
ditio
n,
if th
e
dy
na
mic
d
en
sity
sele
ction
o
r c
ap
ac
ities
o
f oth
er
tha
n
72
0
sec
tors
pe
r
disk
a
re
to
b
e
use
d,
the
c
on
trolle
r m
ust
pr
ov
ide
th
e
ex
ten
de
d
810
in
ter
fac
e
de
scrib
ed
in
S
ec
tion
10
. T
his
e
xte
nd
ed
in
terfa
ce
wa
s fir
st
us
ed
b
y
the
P
ER
CO
M
du
al
de
nsity
d
isk
su
bs
ys
tem
s, a
nd
e
xte
nd
ed
to
su
pp
ort
8"
an
d
dou
ble
sid
ed
d
rive
s o
n
the
A
TR
80
00
d
isk
/p
rin
ter
/R
S2
32
c
on
trolle
r m
an
ufa
ctu
red
b
y
SW
P,
Inc.
Re
cen
tly
sup
po
rt fo
r la
rge
R
AM
dis
ks
a
nd
h
ard
d
isk
driv
es
ha
ve
b
ee
n
ad
de
d
to
the
gro
up
o
f s
up
po
rte
d
de
vic
es
by
in
terp
retin
g
som
e o
f th
e
field
s d
iffer
en
tly.
De
sc
riptio
ns
of
the
new
in
ter
pr
eta
tion
to
su
pp
ort
mo
st o
f th
e h
ard
d
isk
a
nd
R
AM
dis
k
sy
ste
ms
m
an
ufa
ctu
re
d
for
the
A
tari
8-
bit
co
mp
ute
rs
.
Up
to
eig
ht
dis
k
driv
es
(o
r
nin
e if
the
n
inth
is
a
R
AM
dis
k)
ma
y
be
a
cc
esse
d,
bu
t o
nly
o
ne
is
r
eq
uire
d.
Th
e
re
sid
en
t p
art
of
the
o
pe
ratin
g
sy
ste
m
sup
po
rts a
ll d
oc
um
en
ted
fu
nc
tion
s o
f th
e
DO
S
2 o
pe
ratin
g
pa
ge
2 R
ev
ision
4
.3a
sy
ste
m,
so
M
YD
OS
4
su
pp
orts
m
os
t a
va
ilab
le
so
ftwa
re
for
the
AT
AR
I h
om
e
co
mp
ute
rs.
Th
e
me
mo
ry
av
aila
ble
to
a
p
rog
ram
is
a
ffec
ted
o
nly
b
y
the
n
um
be
r
of
files
to
be
o
pe
n
co
nc
urre
ntly
: e
ac
h
dis
k
file
tha
t m
ay
b
e o
pe
n
at
the
s
am
e tim
e
req
uire
s
256
b
yte
s
of
bu
ffer
sp
ac
e.
Me
mo
ry
req
uire
me
nts
a
re
in
de
pe
nd
en
t o
f th
e
nu
mb
er
of
dis
k
dr
ive
s
or
th
e
se
cto
r s
ize
a
nd
d
en
sity
. T
he
ne
ed
fo
r a
256
by
te
bu
ffer
for e
ac
h
co
nc
ur
re
ntly
o
pe
n
file
me
an
s
tha
t p
rog
ram
s
tha
t k
ee
p
larg
e
nu
mb
ers
o
f file
s
op
en
w
ill h
av
e
less
m
em
ory
a
va
ilab
le
tha
n
un
de
r D
OS
2
an
d
as
a
res
ult s
om
e
pr
og
ra
ms
(m
ostly
o
lde
r
ve
rsio
ns
o
f co
mp
ilers
a
nd
la
ng
ua
ge
in
ter
pre
ters
) w
ill n
ot
ha
ve
e
no
ug
h
me
mo
ry
to
run
. W
ith
thre
e
file
bu
ffers
a
nd
n
o
res
ide
nt
driv
ers
(s
uc
h
as
for
RS
23
2 s
up
po
rt)
, M
YD
OS
4
pe
rm
its
bin
ar
y
pr
og
ra
ms
to
lo
ad
as
low
a
s
SlFOO.
MY
DO
S
4.3
a
lso
c
on
tain
s
a
ve
ry
v
ers
atile
R
AM
dis
k
driv
er
tha
n
can
b
e
co
nfig
ure
d
to s
up
po
rt m
os
t av
aila
ble
m
em
or
y e
xp
an
sio
n
pro
du
cts
fo
r
the
A
tari 8
-b
it co
mp
ute
rs
(the
prim
ar
y
re
qu
ire
me
nts
a
re
tha
t th
e
me
mo
ry
b
e
ac
ce
ss
ed
th
rou
gh
a
16
K
me
mo
ry
w
ind
ow
fro
m
$40
00
to
$7FF
F,
an
d
tha
t th
e
ma
pp
ing
fu
nc
tion
b
e s
imila
r to
th
at
of
eith
er
th
e
Ax
ion
o
r 130X
E
ex
ten
de
d
me
mo
ry).
III. M
EN
U
FU
NC
TIO
NS
Th
e m
enu
p
rov
ide
d
by
M
YD
OS
4
ide
ntifie
s
20
co
mm
on
ta
sk
s
tha
t m
igh
t n
ee
d
to
be
d
on
e.
Ra
the
r
tha
n
ha
vin
g
to
wr
ite a
u
tility
pro
gra
m
(on
ly
a
few
lines
o
f B
AS
IC
wo
uld
p
erfo
rm
mo
st
of
the
me
nu
fu
nc
tion
s)
or
ev
en
r
em
em
be
r
the
n
am
e
an
d
form
at
of
a
DO
S
co
mm
an
d,
thes
e ta
sk
s
ca
n
be
h
an
dle
d
by
e
nte
rin
g
a
sin
gle
le
tter
. M
YD
OS
4
res
po
nd
s
with
a
q
ue
stio
n
ask
ing
fo
r th
e
de
tails
o
f th
e o
pe
ratio
n
(wh
ich
file
, w
ha
t d
en
sity
, "a
re
y
ou
su
re?
" o
r w
ha
tev
er
else
it
mig
ht
ne
ed
to
kn
ow
). Afte
r y
ou
en
ter
th
e
re
ma
inin
g
info
rma
tion
, th
e
fun
ctio
n
is
pe
rfo
rm
ed
a
nd
a
no
the
r
pr
om
pt
is d
isp
lay
ed
.
Yo
u
sh
ou
ld
no
tice
tw
o
inte
res
ting
th
ing
s
ab
ou
t th
e m
enu
: th
e s
ec
on
d
line
o
n
the
s
cre
en
id
en
tifies
the
d
isk
d
rive
s
pr
es
en
t o
n
the
sy
ste
m
an
d
wh
at
the
y
ap
pe
ar
lo
MY
DO
S 4
to
be
(s
ing
le o
r d
ou
ble
d
en
sity
, R
AM
dis
k
or
h
igh
ca
pa
city
h
ar
d
dis
k). T
he
n
ex
t lin
e
de
sc
rib
es
th
e
cu
rr
en
t d
efa
ult
dire
cto
ry
(th
at
dire
cto
ry
us
ed
w
he
n
a
dis
k
is
refe
ren
ce
d
by
'D
:' (w
itho
ut a
u
nit
nu
mb
er
afte
r the
'D
'l. T
he
s
ec
on
d
thin
g to
no
tice
is
tha
t a
fter
c
om
ma
nd
s
fill th
e
sc
ree
n,
the
m
en
u
'rolls
' o
ff th
e
lop
: so
me
D
OS
pro
gra
ms
k
ee
p
the
me
nu
, M
YD
OS
4
do
es
no
t. T
his
p
er
mits
m
ore
in
form
atio
n
to
be
sh
ow
n
on
the
s
cr
ee
n
wh
en
a
Jo
ng
s
eq
ue
nc
e
of
co
mm
an
ds
is
ne
ed
ed
to
p
erfor
m
a
fun
ctio
n
or
w
he
n
a
dire
cto
ry
is b
ein
g
)isle
d
or
s
ev
era
l file
s
ar
e
be
ing
co
pie
d.
To
re
sto
re
the
m
en
u
to
the
s
cree
n, ju
st
typ
e
RE
TU
RN
a
nd
th
e
initia
l s
cr
ee
n is
res
tore
d.
So
me
co
mm
an
ds
r
eq
uire
fu
rthe
r in
for
ma
tion
to
pr
ev
en
t ac
cid
en
tal d
am
ag
e
t o
yo
ur
d
isk
file
s:
the
'I'
com
ma
nd
a
nd
th
e
'J'
co
mm
an
d
bo
th
req
uir
e
co
nfirm
atio
n
(thro
ug
h
an
a
dd
ition
al
ke
y
en
try
) b
efo
re
dis
troy
ing
th
e
des
tina
tion
d
isk
. T
o
ab
ort
eith
er
o
pe
ra
tion
w
itho
ut
da
ma
gin
g
an
y
exis
ting
d
isk
files
, s
imp
ly
pre
ss
th
e
RE
SE
T
or
BR
EA
K k
ey
s.
Th
e
'D',
'E',
pag
e 3
Re
vis
ion
4
.3a
'F'
an
d
'G'
co
mm
an
ds
(d
ele
te,
ren
ame
, lo
ck
an
d
un
loc
k)
all
req
uire
a
n
ex
plic
it file
s
pe
cific
atio
n.
All
oth
er
c
om
ma
nd
s
as
su
me
the
driv
e
co
nta
inin
g
the
d
efa
ult
dire
cto
ry
o
r a
ll th
e
files
in
the
d
efa
ult
dire
cto
ry
(de
pe
nd
ing
on
w
he
the
r
the
co
mm
an
d
affe
cts
an
e
ntire
d
riv
e o
r
a
se
t o
f file
s).
Dis
k
dr
ive
s
pe
cific
atio
ns
a
nd
file
sp
ecifica
tion
s
are
m
ad
e
us
ing
th
e
sa
me
ru
les
: if
on
ly
a
dr
ive
is
s
pe
cifie
d
an
d
file d
ata
is
re
qu
ired
, a
ll files
on
th
at
dr
ive
(or
in
the
ca
se
o
f th
e
'K'
'L'
an
d
'N'
co
mm
an
ds
to
s
av
e a
nd
lo
ad
p
rog
ram
s,
the
firs
t file
on
th
at
driv
e)
will
be
th
e a
ss
um
ed
ch
oic
e.
A
driv
e
is
sp
ec
ified
w
ith
a
':' (m
ea
nin
g
the
de
fau
lt d
rive
), a
n
um
be
r
(with
o
r w
itho
ut a
tra
iling
':') o
r th
e
cap
ital
lette
r 'D
' fo
llow
ed
b
y a
n
op
tion
al
nu
mb
er
an
d
a
re
qu
ire
d
':'. If y
ou
w
ish
to
s
pe
cify
th
e
file o
r s
et o
f file
s
to
be
re
fere
nc
ed
, th
e
driv
e
form
at m
us
t in
clu
de
a
':'
or
it m
us
t b
e
om
itted
e
ntir
ely
D
l:Te
st.o
bj,
l:TE
ST
.AS
M,
or
D2
TE
ST
(re
ally
D
l:D2
TE
ST
) a
re
va
lid
file
na
me
s,
bu
t d
l:Tes
t.ob
j or
lTE
ST
.AS
M a
re n
ot.
Th
e
file
na
me
its
elf
is
eith
er
fully
sp
ec
ified
(re
fer
rin
g
to exa
ctly
o
ne
file
o
n
the
d
isk
) or
inc
lud
es
"w
ild
ca
rd"
ch
ara
cte
rs
(sp
ec
ifyin
g a
s
et o
f ze
ro
or
mo
re
files
). A
fu
lly
sp
ec
ified
file
n
am
e
con
sis
ts
of
on
e to
e
igh
t c
ha
rac
ters
fo
llow
ed
b
y
a
pe
riod
('.'l
an
d
ze
ro
to
th
ree
a
dd
ition
al
ch
ara
cte
rs.
Th
e
first
ch
ara
cte
r
in
the
file
n
am
e
mu
st
be
a
n
up
pe
r o
r lo
we
r ca
se
lette
r, a
n
un
de
rsc
ore
('_') or
the
c
ha
rac
ters
'@
' o
r "
'· T
he
"
' is
th
e
AT
AR
I d
iam
on
d
gra
ph
ic.
Th
e
rem
ain
ing
c
ha
rac
ter
ma
y
be
in
th
at
se
t o
r o
ne
o
f th
e
dig
its
0-
9.
Th
e
"w
ild
ca
rd"
c
ha
rac
ters
a
re
the
c
ha
rac
ters
'*
' a
nd
'?
': th
e c
ha
rac
ter
'*' o
r th
e
se
qu
en
ce
'*.'
en
d
eith
er
the
8 c
ha
ra
cte
r
or
th
e
3 c
ha
rac
ter
fie
ld
in
the
file
n
am
e
an
d
ma
tch
a
ll p
os
sib
le
ch
ara
cte
rs
. T
he
c
ha
racte
r '?
' m
atc
he
s
an
y
sin
gle
file
n
am
e
ch
ara
cte
r.
In
ad
ditio
n
to
the
m
ain
d
ire
cto
ry
(c
on
tain
ing
u
p
to
61 file
s
or
dir
ec
torie
s)
ea
ch
M
YD
OS
4
dis
k
ma
y
als
o
co
nta
in
ad
ditio
na
l d
irec
torie
s o
f 6
4 file
s
ea
ch
. If
the
m
ain
d
irec
tory
co
nta
ine
d
the
d
irec
tory
file
B
AS
a
nd
th
e
file
GR
AP
HIC
! w
ere
in
th
e
dire
cto
ry
file
BA
S,
it c
ou
ld
be
re
fere
nc
ed
w
ith
the
file
na
me
, B
AS
:GR
AP
HIC
l. If
ins
tea
d,
GR
AP
HIC
! w
ere
in
th
e
dire
cto
ry
G
R.d
ir
wh
ich
in
tu
rn
we
re
in
BA
S,
the
n
the
re
fere
nc
e
wo
uld
b
e
to
BA
S:G
R.d
ir:GR
AP
HIC
l (a
nd
s
o o
n
with
as
m
an
y
na
me
s
as
ne
ed
ed
). B
ec
au
se
th
er
e
is n
o lim
it to
th
e n
um
be
r
of
dir
ec
torie
s
on
a
d
isk
(o
the
r
tha
n
the
b
uffe
r
siz
e
of
pro
gra
ms
us
ing
th
e
dir
ec
torie
s
an
d
nu
mb
er
o
f a
va
ilab
le s
ec
tors
o
n th
e
dis
k),
a s
ing
le
dis
ke
tte
ca
n
co
nta
in
hu
nd
re
ds
of
files
if
ne
ces
sa
ry
.
Ea
ch
d
ire
cto
ry
is
a
8
se
cto
r file
to
its
pa
re
nt
dir
ec
tor
y.
Th
us
it
is
limite
d
to
64 file
s
or
su
bd
ire
cto
ries
exa
ctly
lik
e
the
8 s
ecto
r ro
ot
dir
ec
tor
y.
If a
d
isk
d
ire
cto
ry
in
clu
des
th
e
files
TE
ST
.AS
M,
TE
ST
.OB
J,
TE
ST
.C,
TE
ST
.AL
M,
TE
AS
ET
.DO
C,
TR
AC
E.F
IL,
an
d
BE
TS
.LS
T,
the
s
pe
cific
atio
n
"l*·*"
will
no
t m
atc
h
an
y
file n
am
e (s
inc
e
"t"
an
d
"T
"
are
n
ot
the
s
am
e
lette
r to
M
YD
OS
4
). Th
e
sp
ec
ifica
tion
"TU
"
will
ma
tch
a
ll b
ut "
BE
TS
.LS
T"
(s
inc
e
the
oth
ers
a
ll b
eg
in
with
th
e le
tter
"T"
). T
he
sp
ec
ifica
tion
"?
E?
? ·*
" w
ill m
atc
h
the
firs
t fo
ur
files
an
d
the
la
st
on
e
(sin
ce
the
8
ch
ar a
cte
r p
ar
t of
the
file n
am
e m
us
t h
av
e n
o
mo
re
tha
n
4 c
ha
rac
ters
in
it a
nd
th
e s
ec
on
d
ch
ara
cte
r m
us
t b
e
an
"
E" ).
Th
e
sp
ec
ifica
tion
"*?
" w
ill
pa
ge
4
Re
vis
ion
4
.3a
ma
tch
on
lv
the
file
TE
ST
.C
lsin
ce
it
is
the
on
lv
file n
am
e w
ith
a s
ing
le
Ch
ara
cte
r . in
the
3
ch
ara
cter
field
). T
he
s
p�
cifica
tion
"?
??
?E
U'"
will
ma
tch
th
e
files
TE
AS
ET
.DO
C
an
d
TR
AC
E.F
IL
an
d
no
ne
o
f th
e
oth
er
s
(sin
ce
th
e
8 c
ha
rac
ter
pa
rt o
f th
e
file
na
me
m
us
t h
av
e
at
lea
st
5 c
ha
rac
ter
s
an
d
the
fifth
mu
st b
e a
n
"E"
),
Wh
er
e
mo
re
tha
n o
ne
file
na
me
is
as
ke
d
for
, the
fir
st m
ay
be
om
itted
b
y
sta
rtin
g
the
r
es
po
ns
e
with
a
s
pa
ce o
r c
om
ma
, a
nd
th
e
las
t m
ay
be
om
itted
b
y
en
din
g
the
lin
e
with
a
co
mm
a
(the
s
pa
ce
c
an
no
t b
e u
se
d
he
re
sin
ce
tra
iling
s
pa
ce
s
are
ig
no
red
). If
bo
th
file
na
me
s
ar
e
en
ter
ed
, th
ey
m
ay
b
e
se
pa
ra
ted
w
ith
eith
er a
s
pa
ce
or
a
co
mm
a.
So
me
co
mm
an
ds
m
ay
b
e m
od
ified
us
ing
a
lette
r follo
win
g
the
ch
ara
cte
r
'I'
afte
r th
e file
na
me
(fo
r e
xa
mp
le,
1/A
o
r D
l:TE
ST
IA
). T
he
le
tter
us
ed
(th
e
mo
difie
r)
ge
ne
rally
m
ean
s th
e
sam
e th
ing
if
it is
allo
wed
. In
va
lid
mo
difie
rs
a
re
alw
ay
s ig
no
red
w
ith
no
er
ro
r
ind
icatio
n.
Th
e m
od
ifier
'I A
' ca
us
es
th
e
re
su
lts
to
be
ap
pe
nd
ed
to
th
e
en
d
of
an
e
xis
ting
file
. T
his
is a
pp
lica
ble
to
'C'
(cop
y)
an
d
'A'
(dir
ec
tory
) co
mm
an
ds
. T
he
m
od
ifier
'I
N'
ca
us
es
th
e
de
stina
tion
d
isk
fo
rm
attin
g
to
be
s
kip
pe
d
(sav
ing
a
bo
ut
a
min
ute
) w
he
n
us
ed
in
the
'I'
(initia
lize}
an
d 'J
' (d
up
licate
d
isk
} co
mm
an
ds
. It
pr
ev
en
ts
the
q
ue
stion
s
as
ke
d
be
fore
c
ha
ng
ing
e
ac
h
file
if it
is u
se
d
in
the
'D
' (d
ele
te),
'F'
(loc
k)
an
d
'G'
(un
loc
k)
com
ma
nd
s.
(We
b
en
d
the
ru
le
so
re
ce
ntly
m
en
tion
ed
. In
b
oth
case
s, p
art o
f th
e
fun
ctio
n
is
sk
ipp
ed
se
e?
)
Th
e 'I
X'
co
mm
an
d
ca
us
es
M
YD
OS
4
to
pa
use
a
t th
e
en
d
of
ea
ch
rea
d
or
write
p
ass
wh
en
c
op
yin
g
da
ta
to
allo
w
yo
u
to
ch
an
ge
d
isk
s
(pe
rm
itting
y
ou
to
co
py
fro
m
on
e
dis
k
to
an
oth
er
with
a
sin
gle
d
riv
e,
ev
en
if
tha
t d
riv
e a
pp
ea
rs
to
M
YD
OS
4
to
be
tw
o
driv
es
). Th
is o
ptio
n
su
pp
or
ts
dis
k
driv
es
th
at
ha
nd
le in
cr
eased
ca
pa
city
by
m
ak
ing
a
s
ing
le
dis
ke
tte
ap
pe
ar
to
be
o
n
mo
re
tha
n
on
e d
rive
a
t a
tim
e,
as
w
ell
as
disk
d
rive
s
tha
t se
lec
t de
ns
ity
thro
ug
h
the
d
riv
e
nu
mb
er
(1-
4 a
re
s
ing
le d
en
sity
, 5
-8
ar
e
do
ub
le,
for
ex
am
ple
, a
nd
driv
es
1 a
nd
5
ar
e
the
sa
me
p
hy
sica
lly).
Th
is a
lso a
llow
s th
e
wr
iting
of
a
dire
cto
ry o
f o
ne
dis
k o
nto
a
no
the
r a
s a
file
(us
e
the
c
om
ma
nd
'A
' fo
llow
ed
b
y
the
e
ntr
y
"l
,l:DR
VO
l.dirl
X"
) e
ve
n
with
on
ly
a
sin
gle
d
rive
on
th
e s
ys
tem
. T
he
'I
X'
is a
ss
um
ed
if o
nly
o
ne
file
na
me
is e
nte
re
d
in th
e c
op
y c
om
ma
nd
. T
his
e
mu
late
s th
e o
pe
ratio
n o
f th
e A
TA
RI D
OS
2
'O' c
om
ma
nd
wh
ich
is n
ot im
ple
me
nte
d
in M
YD
OS
4
.
To
o
mit
co
py
ing
files
w
ith
ex
ten
sion
s b
eg
inn
ing
w
ith
'S',
the
'I
S'
mo
difie
r c
an
b
e
ap
pe
nd
ed
to
the
eith
er
file
s
pe
cifica
tion
in
th
e
'C'
(co
py
) co
mm
an
d:
for
ex
am
ple
, th
e
line
"
21S
, l"
will
co
py
a
ll file
s n
ot
ma
tch
ing
th
e
string
•
.S?
?
from
driv
e
2 to
d
riv
e
1.
JV.
TH
E
ME
NU
C
OMMAN
DS
;..
Lis
t a
Dir
ec
tor
y
or
a
Se
t of F
iles
Th
e 'A
' co
mm
an
d
will
list th
e file
s o
n
a
dis
k
with
th
eir
siz
es
, fo
llow
ed
by
a
line
sp
ec
ifyin
g
the
nu
mb
er o
f free
se
cto
rs
on
th
e d
isk
. If
the
line
sta
rts w
ith
an
'*'.
the
file h
as
be
en
lo
ck
ed
a
nd
m
ay
n
ot
be
m
od
ified
or
de
lete
d
with
ou
t first
be
ing
u
nlo
ck
ed
. A
':'
be
fore
th
e file
n
am
e
ma
rk
s
tho
se file
s th
at a
re
d
irec
tories.
Th
ese
file
s c
an
no
t b
e r
ea
d o
r wr
itten
a
s
oth
er
files
b
ut
on
ly
ac
ce
ss
ed
as
dire
cto
ries
or
de
lete
d
(if th
e
dir
ec
tory
pa
ge
5 R
ev
ision
4
.3a
is e
mp
ty),
File
le
ng
ths
a
nd
th
e
nu
mb
er
of
free
se
cto
rs a
re r
ep
orte
d
as
4 d
igit
de
cim
al
nu
mb
er
s
(mo
st o
the
r A
tari
DO
Ss
rep
ort
the
va
lue
s
as
3 d
igit
nu
mb
er
s).
If th
e
nu
mb
er
o
f fre
e
se
cto
rs
o
n a
d
rive
e
xc
ee
ds
9
99
9,
the
fre
e
sec
tor
line
w
ill c
on
tain
a
5
dig
it n
um
be
r,
an
d
its
len
gth
th
en
w
ill be
the
sa
me
a
s
the
file
d
ata
lin
es
--
this
ma
y
ca
use
p
ro
ble
ms
w
ith
som
e p
rog
ram
s th
at d
o
no
t d
ete
ct th
is
line
b
y
exa
min
ing
th
e
firs
t ch
ara
cte
r la
file
line
if
it is
'O'
or
'*' a
nd
th
e
free
se
cto
r lin
e
if it
is
a
dig
it), A
lso,
if th
e
nu
mb
er
of
se
cto
rs
in
a
file
is
gr
ea
ter th
an
9
99
9,
the
re
will
be n
o
bla
nk
b
etw
ee
n
the
3
ch
ara
cte
r file
ex
ten
sion
a
nd
th
e
file size
(so
th
e lin
e
will
re
ma
in
the
sa
me
le
ng
th).
Th
is
wa
s n
ee
de
d
to
re
tain
th
e
do
ub
le
colu
mn
d
ire
cto
ry
lis
t, A
ND
D
OE
S
NO
TA
PP
LY
IF
A
D
ES
TIN
AT
ION
F
ILE
N
AM
E
IS
SP
EC
IFIE
D
(or
if
the
dire
cto
ry
is -r.;a d
fro
m
BA
SIC
o
r fr ;,
m
a p
rog
ram
). D
ire
cto
rie
s
rea
d
from
p
rog
ram
s
will g
et
fou
r o
r fiv
e d
igit
file
sizes
an
d
som
e
dir
ec
tor
y
line
s
will
be
on
e
ch
ara
cte
r lo
ng
er
if a
ny
su
ch
h
ug
e
files
ex
ist o
n
the
d
isk
.
No
in
dic
atio
n
is
ma
de
o
f the
fo
rma
t o
f th
e
file
bu
t A
TA
RI
DO
S
1,
AT
AR
I D
OS
2,
an
d
MY
DO
S
4 a
re
the
o
nly
th
ree
s
up
po
rted
file
form
ats
, an
d
the
D
OS
1
form
at
will
be
dro
pp
ed
w
ith
the
re
lea
se
of
MY
DO
S
4.4
. S
pa
rtaD
OS
, D
OS
/ A
+ V
er
sio
n
4 o
r A
tari
DO
S
2.5
files
mu
st b
e co
nv
erte
d
to
sing
le
or
do
ub
le d
en
sity A
tari
DO
S
2 file
s first
in o
rd
er
to
b
e u
sab
le fro
m
MY
DO
S
4.
Se
e
Se
ctio
n
6 fo
r fu
rth
er
d
ire
cto
ry
info
rma
tion
if
yo
u
ne
ed
m
ore
d
eta
il th
an
th
e
'A'
co
mm
an
d
pro
vid
es
.
Th
is
co
mm
an
d
will
list th
e
dir
ec
tory
in
form
atio
n
to
the
s
cr
ee
n
if o
nb
· o
ne
file
s
pe
cific
atio
n is
e
nte
re
d.
If two
a
re e
nte
re
d,
the
secon
d
is
tak
en
a
s
a
de
stin
atio
n
file
an
d
will
be
o
ve
rw
ritte
n
(or
a
pp
en
de
d
to
if th
e
/A
fla
g
is
us
ed
) w
ith
the
d
ire
cto
ry
d
ata
. T
he
e
ntr
y
"l
,P:"
will
wr
ite
the
d
ire
cto
ry
of th
e d
isk
on
d
rive
1
to th
e p
rin
ter
, for
ex
am
ple
.
To
list
the
file
s in
a
s
ub
dir
ec
tory
, e
nte
r th
e
na
me
of
the
d
irec
tory
fo
llow
ed
b
y
a
co
lon
--':'.
Fo
r e
xa
mp
le,
"l
:TE
ST
:BA
S:"
will
list th
e
files
in
the
d
ire
cto
ry
B
AS
w
hic
h in
tur
n is
in
the
d
irec
tory
T
ES
T in
the
ma
in
dir
ec
tor
y o
f th
e
dis
ke
tte
in d
rive
1
.
B.
Run
th
e
Car
trid
ge
Th
e
'B'
co
mm
an
d
retu
rn
s
co
ntro
l to
the
ca
rtr
idg
e
in
the
left ( o
r o
nly
) c
ar
trid
ge
slo
t. If
no
ca
rtr
idg
e
is
pr
es
en
t, a
n
er
ror
is
dis
pla
ye
d,
an
d
no
thin
g
ha
pp
en
s.
No
a
dd
ition
al
info
rma
tion
is
re
qu
ired
, so
if a
c
artrid
ge
is
pr
es
en
t it
is
en
tere
d
afte
r lo
ad
ing
M
EM
.SA
V
(if the
la
st loa
d
co
mm
an
d
we
re
an
'N
') or
imm
ed
iate
ly
(if th
e la
st loa
d
co
mm
an
d
we
re
an
'L
').
C.
Cop
y
a
File
or
a
Se
t of
File
s
pa
ge
6 R
ev
isio
n
4.3a
Th
e 'C
' co
mm
an
d
is
us
ed
Lo
m
ak
e
an
oL
he
r c
op
y
of
on
e o
r m
ore
files
of
da
ta.
Th
e Lw
o
file s
pe
cifica
Lion
s a
sk
ed
fo
r a
fLer
en
Ler
ing
Lhe
'C'
ide
nLify
th
e
sou
rce
a
nd
Lh
e d
esLin
aLio
n
of
the
info
rma
tion
b
ein
g
co
pie
d.
Eith
er
rnay
b
e fu
lly
spe
cified
d
isk
file
or
a
de
vice
s
pe
cifica
tion
(su
ch
a
s E
:, P
: o
r o
ne
of
Lhe
RS
23
2
po
rts R
l: to
R
4:).
Th
e d
es
tina
tion
m
ay
b
e
a
set o
f d
isk
files (s
pe
cifie
d
with
'*'
an
d
'?'s)
on
ly
if th
e s
ou
rc
e
sp
ec
ifies
a
file n
am
e fo
r th
e
de
stin
atio
n
to
use.
Co
pie
s fro
m
a
file set
to
a d
ev
ice
w
ill im
plicitly
w
rite
c
on
se
cu
tive
file
s to
th
e
de
vice
(g
en
era
ting
a
se
t o
f listin
gs
or
a
colle
ctio
n
of
ca
ss
ette
files
for
ex
am
ple
). T
he
so
urce
ma
y
be
a
set
an
d
Lhe
d
es
tina
tion
a
s
ing
le
dis
k
file,
bu
t u
nle
ss th
e
'/A
' mo
difie
r is
spe
cified
to
a
pp
en
d
ea
ch
co
pie
d
file
to
the
e
nd
o
f th
e
pre
vio
usly
co
pie
d
files
, o
nly
th
e
las
t so
ur
ce
file
w
ill re
ma
in
on
th
e
de
stin
atio
n
dis
k.
No
te
tha
t th
e 'C
' c
om
ma
nd
alw
ay
s u
se
s th
e
full
me
mo
ry
s
pa
ce
for
a
c
op
y
op
era
tion
(u
nlik
e A
TA
RI
DO
S
2) a
nd
a
s a
re
su
lt, it
will
alw
ay
s
inv
alid
ate
M
EM
.SA
V
if it is
us
ed
. A
ny
p
en
din
g
pro
gra
m
ca
nn
ot
be
r
es
tar
ted
a
fter
a
'C
' or
'J'
com
ma
nd
.
D.
De
lete
a
F
ile o
r
Se
t of
Files
Th
e 'D
' co
mm
an
d
will
remo
ve
all
files th
at
ma
tch
th
e file
s
pe
cifica
tion
e
nte
red
a
sk
ing
fo
r c
on
firma
tion
b
efo
re
ea
ch
on
e
is
re
mo
ve
d.
Th
is
ve
rificatio
n
tha
t th
e file
is
rea
lly
the
on
e
to
be
re
mo
ve
d
ca
n
be
d
isa
ble
d
for
the
d
ura
tion
o
f th
is
sing
le
'D'
com
ma
nd
b
y
ad
din
g
the
c
om
ma
nd
m
od
ifier
'/N
' to
th
e
en
d
of
the
file
sp
ec
ificatio
n.
In
this
ca
se
, a
ll th
e
ma
tch
ing
file
s
will
be
r
em
ov
ed
'qu
ietly
' a
nd
th
e
on
ly
fur
the
r
ind
ica
tion
y
ou
will se
e is
th
e p
ro
mp
t for
the
n
ex
t com
ma
nd
.
E.
Re
na
me
a
F
ile
or
Se
t o
f F
iles
Th
e
'E'
com
ma
nd
c
ha
ng
es
th
e
na
me
o
f th
e so
ur
ce
file
o
r file
s to
m
atc
h
the
sp
ec
ificatio
n
in
the
d
estin
atio
n.
Un
like
o
the
r
file
sp
ec
ificatio
ns
, th
e
de
stin
atio
n
spe
cifica
tion
m
ust
co
ns
ist
of
a
sing
le
file
na
me
: it
mu
st
no
t c
on
tain
a
ny
d
irec_to
ry
na
me
s
or
a
dis
k
driv
e
nu
mb
er
. F
or
ex
am
ple
, "D
Z:T
ES
T:B
AS
IC:N
OT
PN
T.B
AS
,RA
ND
IO.B
AS
" is
the
line
e
nte
re
d
to
ch
an
ge
th
e n
am
e o
f a
file in
th
e
dire
cto
ry
"DZ
:TE
ST
:BA
SIC
". T
o
ch
an
ge
th
e
na
me
o
f th
e
dire
cto
ry
"BA
SIC
" to
"AT
BA
SIC
", th
e
line
w
ou
ld
loo
k
like
"D
Z:T
ES
T:B
AS
IC,A
TB
AS
IC"
.
F.
Lock
a
File
or
Se
t o
f F
iles
Th
e 'F
' co
mm
an
d
limits
a
cc
ess
Lo
the
files id
en
tified
. T
he
files
ma
y
no
t b
e d
eleLed
, r
en
am
ed
, a
dd
ed
Lo
or
rep
lac
ed
w
itho
ut
be
ing
fir
st
un
loc
ke
d
with
th
e
'G'
com
ma
nd
.
pa
ge
7 R
ev
isio
n
�.3
a
Wh
en
a
d
ire
cto
ry
is lis
ted
, th
e files
tha
t h
av
e b
ee
n
loc
ke
d
usin
g
eith
er
th
e
'F'
co
mm
an
d
or
the
'lo
ck
' o
r 'o
pe
n
loc
ke
d'
fun
ctio
ns
p
rov
ide
d
thro
ug
h
CIO
w
ill b
e
ma
rke
d
with
a
n
'*'
in
the
first
colu
mn
. T
he
file
s th
at
ar
e
loc
ke
d
ma
y
be
r
ea
d
or
loa
de
d
an
d
ex
ec
ute
d
no
rm
ally
, o
nly
m
od
ifica
tion
o
r re
mo
va
l a
re
p
roh
ibite
d.
A
Joc
ke
d
dire
cto
ry
ca
nn
ot
be
d
ele
ted
o
r r
en
am
ed
a
nd
n
o
files
m
ay
b
e w
ritte
n
to
it. T
he
file
s a
lrea
dy
in
it
can
b
e m
od
ified
fr
ee
ly,
ho
we
ve
r.
Be
for
e
ea
ch
file
is
Jo
ck
ed
M
YD
OS
a
sk
s
yo
u
for
c
on
firma
tion
w
ith
a
me
ss
ag
e:
for
the
file T
ES
T,
the
messa
ge
w
ou
ld
read
"
Lo
ck
T
ES
T?
". A
ny
a
ns
we
r
bu
t 'Y
' w
ill r
es
ult in
th
e file
no
t be
ing
lo
ck
ed
. Th
e c
on
firma
tion
q
ue
stio
ns
c
an
b
e
sk
ipp
ed
b
y
ad
din
g
'/N
' to
th
e
en
d
of
the
file
s
pe
cific
atio
n.
G.
Un
lock
a
F
ile
or
Se
t o
f F
iles
Th
e
'G'
co
mm
an
d
rem
ov
es
th
e
limita
tion
s im
po
sed
on
a
file
w
he
n
it is
'loc
ke
d'
usin
g
the
'F
' c
om
ma
nd
. It
do
es
n
ot
alte
r th
e
file
or
oth
er
wis
e
ch
an
ge
the
w
ay
th
e
file is
a
cc
esse
d
or
us
ed
. T
he
sa
me
fu
nc
tion
m
ay
b
e
pe
rfo
rme
d
in a
p
rog
ram
th
rou
gh
th
e
CIO
fu
nc
tion
to
'u
nlo
ck
' a
file.
Be
for
e
un
loc
kin
g
ea
ch
file
M
YD
OS
a
sks
for
co
nfirm
atio
n
with
a
q
ue
stion
th
at
mu
st b
e
an
swe
re
d
with
a
'Y
' if
the
file
is to
b
e
un
loc
ke
d;
oth
er
wis
e,
no
a
ctio
n
is
tak
en
a
nd
th
e
ne
xt
co
nfirm
atio
n
qu
es
tion
is
as
ke
d.
To
d
isab
le
the
co
nfir
ma
tion
q
ue
stion
s,
en
ter
'/
N'
afte
r th
e file
s
pe
cific
atio
n
(see
S
ec
tion
IV
.D.,
on
d
ele
ting
file
s,
for
a
mo
1·e d
eta
iled
e
xp
lan
atio
n).
H. W
rite
MYD
OS
4
to a
D
isk
Th
e
'H'
co
mm
an
d
is
use
d
to
ma
ke
a
re
bo
ota
ble
co
py
o
f th
e c
ur
re
nt
MY
DO
S
4 file
s in
m
em
or
y.
Th
e
two
file
s c
rea
ted
o
r r
ew
ritte
n
ar
e
'DO
S.S
YS
' a
nd
'D
UP
.SY
S'.
'DO
S.S
YS
' is
a
n
ima
ge
o
f th
e
pe
rm
an
en
tly
re
sid
en
t file
m
an
ag
em
en
t ro
utin
e
ac
ce
ss
ed
th
rou
gh
C
IO
an
d
the
sm
all
inte
rfac
e
pa
ck
ag
e
tha
t lo
ad
s
an
d
sav
es
M
EM
.SA
V
(an
im
ag
e
of
the
pa
rt o
f m
em
or
y
us
ed
to
h
old
th
e
no
nre
side
nt
pa
rt o
f M
Y D
OS
4 l
an
d
the
se
co
nd
p
art
of
MY
DO
S
4 itse
lf ('D
UP
.SY
S')
. T
he
file 'D
UP
. SY
S'
is a
s
tan
da
rd
lo
ad
file
co
nta
inin
g
the
pa
rt o
f M
YD
OS
4
tha
t is
o
ve
rw
ritte
n
wh
en
a
p
rog
ram
is
loa
de
d
into
m
em
or
y.
Ne
ithe
r o
f th
es e
file
s is
co
mp
atib
le
with
a
ny
oth
er
d
isk
op
era
ting
sy
stem
eith
er
for
the
A
TA
RI
or
an
y
oth
er
ho
me
com
pu
ter
. B
oth
sh
ou
ld
be
tre
ate
d
as
a
sin
gle
o
bje
ct.
Ne
ve
r c
op
y
on
ly
DO
S.S
YS
o
r o
nly
D
UP
.SY
S to
a
dis
k
with
ou
t cop
yin
g th
e
oth
er
.
Th
e
files
w
ritte
n
to
the
d
isk
b
y
the
'H'
com
ma
nd
w
ill r
efle
ct
the
co
nfig
ura
tion
p
ara
me
ter
s
cu
rr
en
tly
in
mem
or
y,
wh
ich
ma
y
be
d
iffer
en
t fr
om
the
o
ne
s
ac
tive
if
the
sy
stem
w
er
e
re
boo
ted
fro
m
the
m
as
ter
d
isk
pa
ge
8
Rev
isio
n 4
.3a
ag
ain
. (S
ee
S
ec
tion
IV
.O.,
con
figu
rin
g
the
sy
ste
m,
for
the
de
finitio
n
of
the
co
nfig
ura
tion
p
ara
me
ter
s p
rov
ide
d
in
the
sy
ste
m
an
d
ho
w
to
sp
ec
ify
a
mo
dified
co
nfig
ura
tion
.)
I. In
itializ
e
a
Dis
ke
tte
Th
e
'I' c
om
ma
nd
is u
sed
to
pr
ep
ar
e
a
ne
w
dis
k
for
u
se
w
ith
the
M
YD
OS
4
op
era
ting
sy
ste
m o
r to
rem
ov
e a
ll th
e
files o
n
an
old
d
isk
. T
he
r
es
ult
of
the
'I'
co
mm
an
d
is
a
com
ple
tely
e
mp
ty
dis
k.
Th
e
on
ly
da
ta
on
th
e
dis
ke
tte is
tha
t s
ystem
p
rov
ided
in
form
atio
n
de
finin
g
the
s
pa
ce
a
va
ilab
le
an
d
the
em
pty
m
ain
d
irec
tory
.
If the
dr
ive
n
um
be
r is
fo
llow
ed
by
a
'I
N'
mo
difie
r,
the
d
isk
ette
w
ill n
ot
be
re
form
atte
d,
bu
t ju
st
'era
sed
'. If
the
d
isk
is
for
ma
tted
w
ith
a
sta
nd
ard
fo
rm
at,
this
is
the
reco
mm
en
ded
(fa
stest )
wa
y
to
re
mo
ve
a
ll th
e
files
on
a
dis
ke
tte,
rath
er
th
an
to
u
se
the
'D
' com
ma
nd
.
A
dis
ke
tte
ma
y
also
b
e
form
atte
d
in
the
A
tari
1050
e
nh
an
ced
fo
rma
t b
y
re
sp
on
din
g to
th
e
qu
estio
n
"En
ter
Y
(o
r
A)
to
form
at
driv
e
1: "
w
ith
an
"A
" (p
re
su
min
g
the
d
rive
is
a
105
0
driv
e
or
com
pa
tible
w
ith
the
10
50
). T
he
d
iske
tte
is,
ho
we
ve
r,
no
t c
om
pa
tible
w
ith
the
d
isk
ette
s
simila
rly
cre
ate
d
by
D
OS
2
.5.
Th
e M
YD
OS
d
isk
ette
w
ill n
ot
be
r
ea
da
ble
b
y
DO
S
2.5
an
d
DO
S
2.5
en
ha
nc
ed
dis
ks
ca
n
be
on
ly
pa
rtially
r
ea
d
by
MY
DO
S.
J.
Du
plic
ate
a
D
isk
ette
Th
e 'J'
co
mm
an
d
cop
ies a
ll th
e
info
rma
tion
fro
m o
ne
d
isk
ette
to
a
no
the
r.
Th
e in
form
atio
n
to
be
co
pied
form
th
e
sou
rce
d
iske
tte is
d
ete
rmin
ed
b
y
sp
ec
ifyin
g a
sta
rting
an
d
an
en
din
g
se
cto
r n
um
be
r. If
the
r
an
ge
is
n
ot
sta
ted
, th
e
secto
rs m
ark
ed
a
s in
u
se
in
the
D
OS
b
it m
ap
(o
n
the
V
TO
C
se
cto
rs
) are
co
pie
d.
A
sec
tor
ran
ge
is
sp
ecifie
d
by
a
dd
ing
two
n
um
be
rs
s
ep
ara
ted
b
y a
d
as
h
an
d
en
clo
sed
in
pa
ren
the
se
s
to th
e e
nd
of
the
dr
ive
sp
ec
ifica
tion
( s). F
or
e xa
mp
le,
to
co
py
secto
rs 19
thro
ug
h
54 (tra
ck
s
1 th
rou
gh
3
) fro
m
driv
e
1 to
d
rive
4,
with
ou
t fo
rma
tting
th
e
dis
ke
tte in
d
rive
4,
the
c
om
ma
nd
lin
e co
uld
b
e "
1 ,41N
( 1 9-
54
)".
If th
e
de
stina
tion
d
isk
is
a
lre
ad
y
a
pro
pe
rly
for
ma
tted
M
YD
OS
4
di s
ke
tte,
the
'IN
' m
od
ifier m
ay
be
en
ter
ed
a
fter
eith
er
driv
e
nu
mb
er
to
skip
th
e
form
attin
g
of
the
d
estin
atio
n
driv
e.
Oth
er
wis
e,
the
d
es
tina
tion
d
i sk
ette
w
ill b
e fo
rma
tted
b
efo
re th
e
da
ta
from
th
e
sou
rc
e
is
co
pie
d
to
it. T
ha
t is,
eith
er
"ll
N,2
" o
r "
1,2
1N
" w
ill c
op
y
from
d
rive
1
to
driv
e
2 w
itho
ut
firs
t fo
rma
tting
th
e d
isk
ette
in
driv
e
2. T
o
cop
y
the
fir
st
two
tr a
ck
s o
f a
disk
ette
w
itho
ut
for
ma
tting
th
e d
iske
tte
bein
g c
op
ied
to
, y
ou
c o
uld
e
nte
r "
llN
,2(1-
36
)" or
"1,21
N(l-
36
)".
If th
e V
TO
C
is
no
t c
on
structed
b
y
Ata
ri D
OS
2,
a
ve
rsio
n
of
MY
DO
S
or
an
oth
er
com
pa
tible
op
era
ting
sys
tem
th
e s
ec
tor
list m
ust
be
s
pe
cified
. A
d
11al
de
nsity
A
tari
DO
S
2.5 d
isk
will
no
t b
e
cop
ied
co
rr
ec
tly
un
les
s
the
pa
ge
9 R
ev
isio
n
4.3a
de
stin
atio
n
is fir
st
form
atte
d
with
the
'I'
com
ma
nd
, th
en
c
op
ied
w
ith
the
'J
' c
om
ma
nd
a
nd
th
e
co
mm
an
d
line
"1
,2/N
(l-
104
0)".
To
co
py
th
e
en
tire
dis
k
from
d
rive
1
to
driv
e
2 a
fter
form
attin
g
the
d
isk
ette
in
d
rive
2
the
c
om
ma
nd
co
uld
b
e "
1,2(1
-72
0)".
Th
is is
the
p
rop
er
wa
y
to
du
plica
te
a
no
n-
MY
DO
S
co
mp
atib
le
dis
ke
tte
(of
cou
rse,
co
pie
s o
f "co
py
p
rote
cte
d"
dis
ks
w
ill n
ot
no
rma
lly
be
u
sab
le
afte
r c
op
yin
g
bu
t d
ata
d
isk
s
for
som
e
wo
rd
pro
cesso
rs a
nd
g
am
es
c
an
b
e b
ac
ke
d
up
th
is
wa
y).
Th
e
dis
k
initia
lizatio
n
do
ne
b
y
the
'J
' co
mm
an
d
is
do
ne
w
itho
ut
er
ror
ch
ec
ks:
this
m
ea
ns
th
at
a
dis
k fo
rma
tted
w
ith
the
'J
' co
mm
an
d m
ay
h
av
e
ba
d
sec
tor
s
(in
the
c
ase
o
f c
rea
ting
a
b
ac
ku
p d
isk
, th
e
disk
w
ill n
ot
be
w
ritten
to
la
ter
so
if th
e
dis
k
is w
ritten
w
ith
write
v
erific
atio
n
an
y
er
ror
in
the
c
ur
re
nt
co
nte
nts
w
ill b
e d
isco
ve
red
b
efo
re
mo
dify
ing
th
e
sou
rce
d
isk
).
If th
e
dis
k
is to
b
e
a
wo
rk
ing
d
isk
, a
m
ore
re
liab
le
ap
pro
ac
h
is
to
initia
lize
the
dis
k
(with
th
e 'I'
com
ma
nd
) a
nd
th
en
co
py
th
e d
ata
u
sing
th
e
'J'
co
mm
an
d
an
d
the
'/
N'
mo
difie
r if
no
b
ad
se
cto
rs
a
re
ide
ntifie
d
(see
th
e
ne
xt
pa
rag
rap
h).
Sin
ce
th
e
'C'
co
mm
an
d
reo
rg
an
izes
the
d
ata
on
th
e
dis
k,
red
uc
ing
se
qu
en
tial
rea
d
time
fo
r a
ll th
e
files
, it
is
a
be
tter
wa
y
to
co
py
th
e
co
nte
nts
of
dis
ks
w
he
n
the
re
ad
tim
e
on
a
d
isk
ette
is
mo
re
imp
orta
nt
tha
n
the
c
op
yin
g
time
. If
a
dis
ke
tte
with
D
OS
.SY
S
an
d
DU
P.S
YS
is
co
pie
d
with
th
e
'J'
com
ma
nd
, th
e
co
py
w
ill a
lso
be
b
oota
ble
b
ut
the
'H
' c
om
ma
nd
m
us
t b
e
use
d
to
rein
stall a
b
oota
ble
D
OS
.SY
S
if th
e
dis
ke
tte
is b
uilt
with
th
e
'C' c
om
ma
nd
.
No
te
tha
t th
e
'J'
com
ma
nd
, lik
e
tha
t in
A
TA
RI
DO
S
2, w
ill u
se
all
of
av
aila
ble
m
em
ory
to
d
up
lica
te
the
d
isk
ette
: th
is m
ea
ns
th
at
if m
em
ory
h
as
be
en
sa
ve
d
us
ing
th
e
ME
M.S
AV
file
, it
will
no
lo
ng
er
be
v
alid
. A
ny
p
en
din
g
pro
gra
m c
an
no
t be
r
es
tarted
a
fter
a
'C'
or
'J' co
mm
an
d.
K.
Sa
ve
M
em
or
y
to D
isk
Th
e
'K'
co
mm
an
d
bu
ilds
a
b
ina
ry
lo
ad
file
c
on
tain
ing
th
e
da
ta
from
th
e
me
mo
ry
are
a
spe
cifie
d,
as
we
ll a
s a
n
initia
lizatio
n
an
d
a
run
v
ec
tor
ad
dre
ss
if sp
ec
ified
. If
the
file
is
no
t to
e
xe
cute
a
n in
itializa
tion
ro
utin
e
on
b
ein
g
load
ed
, th
e
initia
lizatio
n v
ec
tor
sh
ou
ld
be
o
mitte
d.
If it
is n
ot
to
ru
n
on
b
ein
g
loa
de
d, th
e
run
v
ec
tor
sh
ou
ld
also
b
e o
mitte
d
( trailin
g
com
ma
s n
ee
d
no
t be
ty
pe
d
in e
ithe
r).
If e
ithe
r v
ec
tor
is
en
tere
d
as
ze
ro,
tha
t is
e
qu
iva
len
t to
o
mittin
g
it. N
ote
th
at
the
sta
rting
a
nd
e
nd
ing
a
dd
resse
s o
f th
e
pro
gra
m
an
d
bo
th
en
try
po
ints
are
all
spe
cifie
d
as
hex
n
um
be
rs.
If M
EM
.SA
V
is ac
tive
w
he
n
the
'K
' com
ma
nd
is e
nte
red
, th
e
ME
M.S
AV
file
is
lo
ad
ed
b
efo
re
writin
g
the
file
to
th
e
dis
k.
L.
Load
Me
mo
ry
fr
om
a
F
ile
pa
ge
10
R
ev
ision
4
.3a
Th
e
'L' c
om
ma
nd
ta
ke
s a
b
ina
ry
lo
ad
file
fro
m
the
d
isk
a
nd
lo
ad
s it in
to
me
mo
ry
. T
he
lo
ad
file
's
initializa
tion
ro
utin
e(s
) w
ill b
e
ex
ec
ute
d
an
d
the
p
ro
gra
m
starte
d a
t its
run
a
dd
re
ss
u
nle
ss
th
e
'/N'
mo
difie
r is
a
pp
en
de
d
to th
e
file
na
me
giv
en
the
'L'
com
ma
nd
.
Th
is
co
mm
an
d
disa
ble
s th
e
ME
M.S
AV
file
b
efo
re
loa
din
g
an
d
exe
cu
ting
th
e
pro
gra
m.
M.
Run
at
Ad
dr
es
s
Th
e
'M'
co
mm
an
d
is
use
d
to
en
ter
a
p
rog
ram
lo
ad
ed
w
itho
ut
a
ru
n
ad
dre
ss
, o
r to
ju
mp
in
to
an
y
pr
og
ram
w
itho
ut
the
n
ee
d
for
a
retu
rn
a
dd
res
s.
It m
ay
b
e
use
d
to
re
sta
rt
the
c
om
pu
ter
(loa
din
g
the
A
UT
OR
UN
.SY
S
file,
if an
y)
by
sp
ec
ifyin
g
$E
47
7 a
s th
e ju
mp
ad
dr
es
s.
If
ME
M.S
AV
is
a
ctive
(e
na
ble
d
with
th
e
'N'
co
mm
an
d
an
d
no
t s
inc
e
disa
ble
d
by
th
e
'L'
co
mm
an
d), th
e
co
nte
nts
o
f m
em
ory
w
ill b
e
resto
red
fro
m
ME
M.S
A V
b
efo
re
jum
pin
g
to
the
ad
dre
ss
sp
ec
ified
.
N. Loa
d M
EM
.SA
V fro
m
a
File
Th
e
'N'
co
mm
an
d
tak
es
a
b
ina
ry
lo
ad
file
fro
m
the
d
isk
a
nd
lo
ad
s
it in
to
me
mo
ry
. T
he
lo
ad
file
's
initializa
tion
ro
utin
e(s
) w
ill b
e
ex
ec
ute
d
an
d
the
p
rog
ra
m
starte
d
at its
r
un
ad
dr
es
s u
nle
ss
th
e
'/N
' m
od
ifier
is a
pp
en
de
d
to
the
na
me
of
the
file
to
be
lo
ad
ed
. Th
is c
om
ma
nd
e
na
ble
s
the
M
EM
.SA
V
file
be
fore
lo
ad
ing
(a
nd
e
xec
utin
g)
the
p
rog
ram
a
nd
w
he
n
co
ntro
l is
r
etu
rn
ed
to
M
YD
OS
th
e
con
ten
ts
of
me
mo
ry
w
ill b
e
sav
ed
b
ac
k
to
ME
M.S
AV
.
If n
o
file
na
me
is
spe
cifie
d,
the
M
EM
.SA
V
file
usa
ge
is
e
na
ble
d
bu
t n
o
pro
gra
m
is lo
ad
ed
o
r r
un
.
O.
Sy
ste
m
an
d D
riv
e
Con
figura
tion
Th
e
'O'
co
mm
an
d
is
use
d
to
spe
cify
th
e
typ
e
(at
lea
st lo
gic
ally
) o
f th
e
dis
k
dr
ive
s
on
th
e
AT
AR
I co
mp
ute
r
an
d
it is
a
lso
use
d
to
spe
cify
s e
ve
ral
sy
ste
m
co
nfig
ura
tion
p
ara
me
ter
s
su
ch
a
s th
e
nu
mb
er
of
file
bu
ffer
s
pro
vid
ed
o
r w
he
the
r a
R
AM
dis
k
is p
rese
nt.
Th
e
sy
stem
c
on
figu
ratio
n
fun
ctio
ns
, w
hich
a
re
n
ot
sp
ec
ific to
in
div
idu
al
dr
ive
s,
are
s e
lec
ted
b
y
en
ter
ing
a
R
ET
UR
N
wh
en
th
e
pro
mp
t a
sk
ing
fo
r a
d
riv
e
nu
mb
er
is
d
isp
lay
ed
.
Eith
er
th
ree
or
sev
en
c
on
figu
ra
tion
p
ara
me
ter
s
will
be
p
ro
mp
ted
fo
r d
ur
ing
a
sy
stem
co
nfig
ura
tion
: th
ree
if
the
RA
Md
isk
(a
lso
refe
rr
ed
to
a
s m
em
ory
o
r
virtu
al d
isk
s)
is n
ot
to
be
u
sed
o
r se
ve
n
if th
e
MY
DO
S
4 R
AM
dis
k
ha
nd
ler
is to
b
e
use
d.
I f th
e
an
swe
r to
th
e th
ird
q
ue
stio
n
is
'N', th
e
rem
am
mg
fo
ur
qu
es
tion
s
ha
vin
g
to
do
w
ith
the
R
AM
dis
k
will
be
s
kip
pe
d.
Th
e
follo
win
g
tab
le
ex
pla
ins
th
e
sig
nifica
nce
o
f e
ach
pr
om
pt a
nd
its
resp
on
se.
pa
ge
11
R
ev
ision
4
.3a
Ve
rify
WR
ITE
s?
RA
M
dis
k
pre
sen
t?
Size
(K)?
N=d
o n
ot
wr
ite
with
v
er
ify,
else
d
o
ve
rify a
t o
nce
!RE
TU
RN
=
3)
N=
no
RA
M
dis
k o
n th
e
sy
ste
m
(sk
ips
th
e
nex
t 4
qu
estio
ns
as
we
ll), else
th
e
RA
Md
isk
is
en
ab
led
a
nd
th
e
ne
xt
4 resp
on
ses
de
term
ine
w
ha
t k
ind
it
is
Size
of
the
R
AM
dis
k a
rea
in
K
(8
s
ing
le
de
nsity
se
cto
rs
=
lK), th
is
mu
st b
e
a
mu
ltiple
o
f 16
(NI 2
56
K
up
gra
de
=19
2
OR
128
, A
XL
ON
::l12
, de
fau
lt o
r 13
0X
E::
641.
Co
ntro
l A
dd
res
s(H
EX
)? A
dd
ress o
f th
e
me
mo
ry
ma
p
co
ntro
l po
rt: a
RE
TU
RN
sp
ec
ifies
$D
30
1 fo
r th
e
130
XE
. F
or A
XL
ON
R
AM
PO
WE
R
128
, e
nte
r C
FF
F
here
.
Pa
ge
se
qu
en
ce?
RA
M
dis
k
driv
e
no
?
RE
TU
RN
if
us
ing
a
stan
da
rd
Ata
ri 130X
E
or
eq
uiv
ale
nt
RA
Md
isk
. O
the
r
stan
da
rd
va
lue
s are
(1)
for
the
Ne
we
ll in
du
strie
s u
pg
rad
e,
(2)
for
the
R
AM
BO
fro
m
ICD
(o
nly
if n
o e
xte
nd
ed
R
AM
p
rog
ram
s ar
bein
g
use
d:
BA
SIC
X
E,
Sy
nC
alc
, etc
), a
nd
(5) fo
r Ax
ion
or c
om
pa
tible
bo
ar
ds
. T
he
m
ost g
en
era
l re
spo
nse
is
to
list
the
p
ag
e
nu
mb
er
s to
b
e u
sed
a
s 2
he
x
dig
its ea
ch
, sep
ara
ted
b
y c
om
ma
s, an
d
co
ntin
uin
g if
nece
ssary
by
en
din
g
the
line
with
a
com
ma
. T
he
se
qu
en
ce
is e
nd
ed
w
ith
a
"O" if
the
R
AM
dis
k is
13
0X
E co
mp
atib
le
an
d
with
a
"F
F" if it is
A
xio
n
com
pa
tible
.
Driv
e
nu
mb
er
use
d
to a
cce
ss
the
R
AM
dis
k
!RE
TU
RN
for
driv
e
9 o
r a
d
riv
e
nu
mb
er
1-9)
A
RE
TU
RN
d
oe
s n
ot
reta
in
the
c
urre
nt
va
lue
w
he
n
re
sp
on
din
g
to
the
se
qu
es
tion
s, it
ch
an
ge
s
the
se
tting
to a
g
en
era
lly
ac
ce
pta
ble
d
efa
ult.
Also
, a
B
RE
AK
o
r R
ES
ET
w
ill n
ot
lea
ve
th
e
co
nfig
ura
tion
u
nc
ha
ng
ed
. If
the
c
on
figu
ratio
n
pro
ces
s
is a
bo
rte
d
for
a
ny
re
aso
n
yo
u
sh
ou
ld
reb
oot
the
c
om
pu
ter
o
r p
rop
erly
co
mp
lete
th
e
co
nfig
ura
tion
b
efo
re
do
ing
a
ny
thin
g e
lse
with
th
e
co
mp
ute
r.
If in
ste
ad
o
f a
R
ET
UR
N,
a
driv
e n
um
be
r o
r n
am
e
ha
d
be
en
sp
ecifie
d
the
n
tha
t d
rive
w
ou
ld
be
re
con
figu
red
. T
he
fir
st
qu
estio
n
ide
ntifie
s w
he
the
r th
e
driv
e
is
to
be
in
clu
de
d
in
sy
stem
initia
lizatio
n
( an
d
thu
s be
a
va
ilab
le
for
late
r u
se
). If
a
no
n-e
xiste
nt
dis
k
is in
clu
de
d
it d
oe
s n
ot
cau
se
an
y
pro
ble
ms
w
ith
the
sy
stem
: it
simp
ly
cau
ses
tha
t d
isk
to
be
e
xam
ine
d
ea
ch
tim
e
the
s
yste
m
is b
oo
ted
(a
dd
ing
p
er
ha
ps
a
se
co
nd
to
the tim
e
it ta
ke
s to
b
oo
t M
YD
OS
4
1.
pa
ge
12
R
ev
ision
4.3
a
If th
e d
rive
is
ex
clu
de
d
from
th
e s
ys
tem
, n
o
fur
the
r
qu
estio
ns
are
a
sk
ed
. O
the
rwis
e,
the
se
co
nd
q
ue
stio
n
ask
s if
the
d
rive
is
c
on
figu
ra
ble:
is it
like
th
e A
TA
RI
810
d
rive
(with
a
fix
ed
c
on
figu
ratio
n)
or
is it
like
th
e
PE
RC
OM
o
r
AT
R8
00
0
driv
es
. If
the
d
isk
is
n
ot
co
nfig
ura
ble
it
is as
su
me
d
to b
e
a
720
se
cto
r, sin
gle
o
r d
ou
ble
de
nsity
A
TA
RI
810
/8
15/
105
0
dis
k
driv
e.
Th
e th
ird
q
ue
stio
n
is w
he
the
r
the
d
rive
is
a
h
igh
c
ap
ac
ity
driv
e
(do
es
it
use
th
e
mo
difie
d
co
nfig
ura
tion
fo
r
no
n-
flop
py
d
isk
s).
Ge
ne
rally
th
is
sho
uld
b
e
an
swe
red
'N
' if
the
d
rive
is
a
flo
pp
y
dis
k
driv
e
an
d
'Y'
oth
erw
ise.
If th
is
qu
estio
n
is
an
swe
red
'Y
' th
e
on
ly
rem
ainin
g
qu
es
tion
is
the
size
(in
s
ec
tor
s, fro
m
256
to
65
53
5,
of
the
d
riv
e).
Driv
es
up
to
16 m
illion
b
yte
s (M
eg
ab
yte
s)
ca
pa
city
c
an
u
se
d w
ith
MY
DO
S,
an
d
lar
ge
r
driv
es
c
an
us
ua
lly
be
p
artitio
ne
d
to a
pp
ea
r a
s tw
o
or
m
ore
d
rive
s of le
ss
th
an
16
millio
n b
yte
s c
ap
ac
ity.
Driv
es
ex
clu
de
d
fro
m
the
s
ys
tem
c
an
b
e
dy
na
mic
ally
a
dd
ed
b
y
refe
ren
cin
g
the
m
bu
t th
ey
w
ill a
lwa
ys
b
e
trea
ted
a
s 5
1/4
in
ch
8
10
co
mp
atib
le d
rive
s
(the
de
fau
lt co
nfig
ura
tion
).
If th
e fir
st
thr
ee a
nsw
er
s
are
'N'
(do
n
ot
ex
clu
de
th
e d
rive
), 'Y
' (it
is
co
nfig
ur
ab
le), a
nd
'N
' (it
is n
ot a
"s
ma
rt"
or
h
igh
c
ap
ac
ity
driv
e),
the
c
on
figu
ratio
n
is
as
ke
d
for
: Is
the
d
rive
d
ou
ble
side
d,
ho
w
ma
ny
tra
ck
s
ar
e th
er
e
on
th
e
ea
ch
sid
e
of th
e
dis
k, a
nd
a
t wh
at
spe
ed
c
an
it
mo
ve
th
e
rea
d/
write
h
ea
d
ac
ross
the
disk
(w
ha
t is its
ste
p
rate
).
Th
e
firs
t q
ue
stio
n
is a
nsw
ered
w
ith
'Y'
or
'N
' ('Y
' m
ea
nin
g
'ye
s'
it is
a
do
ub
le
side
d
driv
e
an
d
dis
ke
ttes
form
atte
d
on
it
will
be
d
ou
ble
side
d).
Th
e
sec
on
d
qu
estio
n
is
an
swe
re
d
with
3
5,
40
, o
r
80
fo
llow
ed
b
y
a
RE
TU
RN
if th
e d
isk
d
rive
is a
35
tra
ck
, 40
trac
k, o
r 8
0
tra
ck
5
1/4
inc
h
flop
py
d
rive
an
d w
ith
77
if th
e d
rive
is
a
77
tra
ck
8
inc
h
driv
e.
If y
ou
h
av
e
IBM
P
C/A
T
style
h
igh
ca
pa
city
dis
k
driv
es
(l
.2M
b
cap
ac
ity)
yo
u
ma
y
use
77
of
the
8
0
trac
ks
in
hig
h
ca
pa
city
m
od
e
pro
vid
ing
1
Mb
c
ap
ac
ity
by
se
lec
ting
7
7
track
s.
No
o
the
r
nu
mb
er
s
are
a
cc
ep
ted
. T
he
a
ns
we
r
to
this
q
ue
stio
n
spe
cifies
bo
th
the
ty
pe
o
f d
rive
(8
in
ch
/h
igh
ca
pa
city
5 1/
4
inc
h,
or
sta
nd
ard
5
1/4
in
ch
) a
s
we
ll a
s th
e
nu
mb
er
o
f tra
ck
s
pe
r in
ch
a
nd
to
tal
ca
pa
city
o
f th
e
driv
e.
Th
is
an
swe
r is
v
er
y
impo
rtan
t to th
e o
pe
ratio
n
of th
e d
rive
.
Til
e la
st a
ns
we
r
is e
nte
re
d
as
a
c
od
e:
us
e
the
fo
llow
ing
ta
ble
a
nd
th
e
dr
ive
sp
ec
ifica
tion
s to
d
ete
rm
ine
the
p
rop
er
va
lue
.
Co
de
va
lue
0 1 2 3
8 in
ch
ra
te
3 m
s/trac
k
6 m
a/tra
ck
10
m
s/tra
ck
15
ms/tra
ck
P.
Disk
ette
D
en
sity
S
elec
tion
pa
ge
13
5 1/
4 in
ch
ra
te
6 m
s/
trac
k
12 m
s/
trac
k
20 m
s/
trac
k
30 m
s/
trac
k Re
visio
n
4.3
a
Th
e
de
nsity
u
se
d
for
mo
st M
YD
OS
c
om
ma
nd
s
is d
ete
rm
ine
d
by
the
d
ata
w
ritte
n
on
th
e
disk
ette
a
nd
th
e
ope
rato
r n
ee
d
no
t "·o
rr
y
ab
ou
t settin
g
it. T
he
'P
' c
om
ma
nd
is
p
rov
ide
d
to a
llow
fo
rc
ing
th
e
de
ns
ity se
tting
fo
r th
e
form
at
t'I'l co
mm
an
d
an
d
to
pe
rmit
settin
g
the
d
en
sity
for
disk
d
riv
es
an
d
syste
ms
th
at
do
n
ot
au
tom
atica
lly
rec
og
nize
th
e
de
nsity
of a
d
isk
ette
w
he
n
sec
tor
1 is
read
(fo
r e
xa
mp
le,
som
e
Pe
rco
m
and
In
du
s
GT
d
riv
es
).
MY
DO
S
co
mm
an
ds
th
at
acce
ss
a
d
isk
ette
w
ill a
uto
ma
tica
lly
sele
ct th
e
ap
pr
op
ria
te
de
ns
ity,
so
the
'P
' co
mm
an
d
will
ha
ve
n
o e
ffect
on
th
e
dr
ive
if a
ny
c
om
ma
nd
a
cce
ss
ing
th
e
dr
ive
c
on
figu
red
w
ith
the
'P
' c
om
ma
nd
is
e
xec
ute
d
be
fore
th
e
form
at
l'I') co
mm
an
d
or
if
a
pro
gra
m
is r
un
u
sin
g
the
'B
', 'L
' or
'N'
co
mm
an
ds
.
MY
DO
S
ha
s
an
u
nte
ste
d
fea
ture
to
s
up
po
rt th
e
Ata
ri 10
50
e
nh
an
ce
d
de
ns
ity
mo
de
-
-w
he
n
form
attin
g a
d
iske
tte,
an
sw
er
ing
"A
" ra
the
r th
an
"¥
" to
th
e
last
pr
om
pt
will
ca
us
e
MY
DO
S
to
issu
e
an
e
nh
an
ce
d
de
ns
ity
form
at
co
mm
an
d
an
d
will
ca
use
th
e
dis
k
sec
tor
map
d
ata
to
be
writte
n
so
as
to a
llow
u
se
of a
ll 1040
se
cto
rs
on
the
dis
k.
!Un
de
r
no
rm
al
op
era
tion
, MY
DO
S d
oe
s n
ot n
ee
d to
kn
o"
· if
the
d
isk
ette
it
is
rea
din
g o
r w
ritin
g
is fo
rma
tted
as e
nh
an
ce
d
or
sta
nd
ard
d
en
sity
. T
he
d
isk
ette
is
ju
st a
10
40
sec
tor
sin
gle
de
ns
ity
disk
ette
.)
Q.
Cr
eate
A
dd
ition
al
Dir
ec
tor
ies
Wh
en
a
d
isk
ette
is
fo
rma
tted
, a
n
em
pty
d
irec
tory
I th
e
hig
he
st le
ve
l o
r ro
ot
dire
cto
ry
) is
c
rea
ted
. T
his
d
irecto
n·
is c
ap
ab
le
of
ho
ldin
g
up
lo
64
files
or
oth
er
d
irec
torie
s.
If a
dd
ition
al
dire
cto
ries
are
in
stalle
d
in
this
d
irec
tor
y, e
ac
h
of
the
a
dd
ition
al
dire
cto
ries
ca
n
co
nta
in
up
lo
64
files
as
we
ll. A
d
irec
tor
y
is in
sta
lled
in
a
n
ex
isting
d
irec
tory
u
sing
th
e
'Q'
co
mm
an
d
an
d
res
po
nd
ing
to
the
q
ue
stion
o
f w
ha
t th
e
dire
cto
ry
na
me
is w
ith
the
na
me
o
f th
e n
ew
dire
cto
ry.
Fo
r e
xa
mp
le,
if "T
ES
T"
an
d
"BA
S"
are
tw
o
dire
cto
ries
dire
cto
ry
o
f th
e
disk
ette
in
d
riv
e 1,
"l:T
ES
T:C
OM
M"
or
wo
uld
c
rea
te
a
ne
w
dire
cto
ry
in
"TE
ST
" o
r "B
AS
" "l
:NE
W:C
OM
M"
wo
uld
n
ot
cre
ate
a
d
irec
tor
y,
ho
we
ve
r,
if "N
EW
" d
oe
s n
ot
alre
ad
y
ex
ist.
in
the
ro
ot
"l:B
AS
:CO
MM
" re
spe
ctiv
ely
. th
e
dire
cto
ry
A 'Q
' c
om
ma
nd
w
ith
the
re
sp
on
se
"
l:NE
W"
wo
uld
c
rea
te
it, a
nd
a
se
co
nd
'Q
' c
om
ma
nd
w
ith
the
re
spo
nse
"
l:NE
W:C
OM
M"
wo
uld
th
en
c
rea
te
the
n
es
ted
d
irec
tor
y.
Ea
ch
d
irec
tory
ta
ke
s u
p
ex
actly
8
sec
tors
an
d a
fter
it
is cre
ate
d
it m
ay
o
nly
b
e
refe
ren
ce
d
as
a
dire
cto
ry
(follo
we
d
by
a
':' th
at
isl
or
de
lete
d.
An
d
it m
ay
o
nly
b
e
de
lete
d
if it
is e
mp
ty
!if it
ha
s n
o
files
in
it) •
.
A
dire
cto
ry
m
ay
b
e
em
ptie
d
by
u
sin
g
the
'D
' (d
ele
te)
co
mm
an
d
an
d
sp
ec
ifyin
g
the
file
s
"*·*
" o
r
"*·*
IN
" to
re
mo
ve
a
ll th
e
files
in
the
d
irec
tory
.
pa
ge
14
R
ev
ision
4
.3a
You
c
an
m
ost
safe
ly
do
th
is
by
sp
ecifyin
g
the
full
na
me
o
f th
e
direc
tory
: fo
r e
xa
mp
le, D
5:M
SG
BA
SE
:SE
PT
19
83
:*.*
/N
R.
Se
t th
e
De
fau
lt D
irec
tory
Th
e 'R
' co
mm
an
d
is u
sed
to
sele
ct
a
dire
cto
ry
to
be
use
d
wh
en
a
file
is re
fere
nc
ed
w
itho
ut
the
d
rive
nu
mb
er:
tha
t is,
wh
en
file
n
am
es
suc
h
as
"TE
ST
l.BA
S"
or
"D:N
EW
CO
DE
" o
r
ev
en
"
:BIG
FIL
E"
are
u
sed
, th
ey
a
re
assu
me
d
to
be
in
th
e
de
fau
lt d
irec
tor
y.
Pr
og
ra
ms
ru
n
un
de
r
MY
DO
S
4 ca
n
acce
ss
th
e
co
nte
nts
o
f th
e c
ur
ren
t de
fau
lt d
ire
cto
ry
b
y
us
ing
a
file
na
me
o
f th
e
form
"D
: .•• " w
ithou
t a
d
rive
n
um
be
r e
xp
licitly
en
ter
ed
.
Th
e
dire
cto
ry
is
set
by
inse
rting
th
e
dis
ke
tte
with
th
at
dire
cto
ry
on
it
into
the
de
sir
ed
d
riv
e,
the
n e
nte
rin
g
the
file
n
am
e o
f th
e
dire
cto
ry
with
n
o
trailin
g
':'.
Th
e
pro
gra
m
ma
y
als
o
se
t th
e
de
fau
lt d
irec
tor
y
by
c
allin
g
the
C
IO
Fu
nc
tion
co
de
41
(se
t d
irec
tory
) rou
tine
.
If the
d
isk
ette
in
th
e
driv
e
con
tain
ing
the
d
efa
ult
dire
cto
ry
is
rep
lace
d,
or
if the
d
efa
ult
dire
cto
ry
o
n
a
dis
ke
tte
is d
ele
ted
, th
e
de
fau
lt sh
ou
ld
be
re
de
fine
d.
Th
e
on
e
ex
ce
ptio
n
is
if th
e
de
fau
lt d
ire
cto
ry
is
the
roo
t d
irec
tory
on
a
d
isk
ette
: b
eca
use
o
nly
th
e
root
dir
ec
tor
y
is
at
the
sa
me
lo
catio
n o
n a
ll d
isk
ette
s.
S.
Se
t th
e
RA
Md
isk
D
rive
N
um
be
r
Th
e
'S'
co
mm
an
d
pe
rm
its
the
driv
e
nu
mb
er
a
ss
ign
ed
to
th
e
RA
Md
isk
to
b
e
ch
an
ge
d
ea
sily,
with
ou
t re
en
ter
ing
th
e
full
sy
ste
m
co
nfig
ura
tion
, u
sin
g th
e
'O'
co
mm
an
d.
In
res
po
nse
to
th
e p
ro
mp
t, ju
st e
nte
r th
e
ne
w
driv
e
nu
mb
er
a
nd
p
re
ss
th
e
RE
TU
RN
k
ey
.
V.
Se
t Write
V
erify
O
N o
r O
FF
Th
e
'V'
co
mm
an
d
tur
ns
o
n o
r off
ve
rific
atio
n
(rea
d
ba
ck
) of
da
ta
wr
itten
to
d
isk
d
rive
s (o
the
r th
an
the
R
AM
dis
k).
MY
DO
S
doe
s
no
t s
up
po
rt
a
tru
e file
d
ata
v
erific
atio
n.
Th
e
ha
rd
wa
re
ve
rify
fun
ctio
n
do
es
, h
ow
ev
er
, iri
sure
th
at th
e d
ata
wr
itten
ca
n
be
re
ad
b
ac
k
an
ins
tan
t late
r.
Th
is
is m
uc
h
mo
re
re
liab
le
tha
n
no
v
erific
atio
n
at
all
an
d
it w
ill c
atc
h
pe
rha
ps
80
% o
f all
failu
res
to w
rite
th
e
sec
tor
da
ta
pr
op
erly
to
th
e
dis
k
( driv
e
sp
ee
d
pr
ob
lem
s
an
d
inc
or
rec
tly
sea
ted
d
isk
ette
s
will
no
t b
e c a
ug
ht).
v. F
ILE
MAN
AG
ER
F
UN
CT
ION
S
PR
OV
IDE
D
TH
RO
UG
H
CIO
pa
ge
15 R
ev
ision
4
.3a
MY
DO
S
4 s
up
po
rts
a
ll C
IO
ca
lls su
pp
orte
d
by
A
TA
RI
DO
S
2, w
ith
mo
difica
tion
s
to
the
O
PE
N
(Fu
nc
tion
c
od
e
3)
an
d
the
F
OR
MA
T
(Fu
nc
tion
c
od
e
25
4)
fun
ctio
ns
.
Th
ree a
dd
ition
al
CIO
fu
nc
tion
s
ha
ve
(F
un
ctio
n
cod
e
34
), S
ET
D
IRE
CT
OR
Y
ME
MO
RY
(F
un
ctio
n c
od
e
39
).
be
en
a
dd
ed
: M
AK
E
(Fu
nc
tion
c
od
e
41
) D
IRE
CT
OR
Y
an
d
LO
AD
Th
e
OP
EN
fu
nc
tion
in
A
TA
RI
DO
S
2 d
oe
s n
ot
use
th
e
da
ta
pro
vid
ed
in
th
e A
UX
2
by
te,
bu
t in
M
YD
OS
4
, wh
en
th
e
AU
Xl
by
te
is
8 (th
e
file
is
op
en
ed
for
c
rea
tion
or
rep
lac
em
en
t), th
e
AU
X2
b
yte
c
on
tain
s
thre
e
flag
s
tha
t co
ntr
ol th
e
file fo
rm
at a
nd
w
he
the
r it w
ill b
e
cre
ate
d
loc
ke
d
or
no
t.
If AU
X2
b
it 1
is
set,
the
file
w
ill b
e
wr
itten
in
the
or
igin
al A
TA
RI D
OS
1
for
ma
t if
the
d
isk
is
sin
gle
sid
ed
, s
ing
le
de
ns
ity;
oth
er
wise
, it
will
be
ig
no
red
: th
e
or
igin
al
for
ma
t is
n
ot
via
ble
fo
r 2
56
b
yte
se
cto
rs o
r d
isk
s
with
m
ore
th
an
10
23
se
cto
rs
.
If A
UX
2
bit
2 is
s
et, th
e file
w
ill be
wr
itten
in M
YD
OS
4 fo
rm
at, a
nd
m
ay
c
on
tain
se
cto
rs
be
yo
nd
ab
solu
te
secto
r 10
23
. Su
ch
a
file
ma
y
no
t (e
as
ily)
be
re
ad
b
y
pr
og
ra
ms
n
ot
ru
nn
ing
w
ith
MY
DO
S.
Th
is
is
the
o
nly
form
at
use
d
with
h
igh
c
ap
ac
ity
dis
ks
.
If AU
X2
bit
5 is
s
et,
the
file
w
ill b
e w
ritten
w
ith
the
'L
OC
KE
D'
bit in
th
e
dire
cto
ry
se
t in
itially
. T
his
is
p
rov
ide
d
for
use
b
y
mu
lti-ta
sk
ing
fu
nc
tion
s (s
uc
h
as
a
p
rin
t sp
oo
ler
, se
qu
en
tial
file
pre
-re
ad
ing
fu
nc
tion
o
r o
the
r e
nh
an
ce
me
nts
o
ne
m
igh
t w
an
t to
m
ak
e
to
the
sta
nd
ard
O
S
or
D
OS
pro
vid
ed
fu
nc
tion
s).
Th
e
FO
RM
AT
fu
nc
tion
in
A
TA
RI
DO
S
2 d
oe
s
no
t p
rov
ide
fo
r a
ny
v
aria
tion
s to
th
e
stan
da
rd
dis
k u
sag
e:
in
MY
DO
S
4,
the
c
on
ten
ts
of
the
A
UX
l a
nd
A
UX
2
by
tes
a
re
use
d
to
sp
ec
ify
the
n
um
be
r o
f se
cto
rs on
th
e
disk
b
ein
g
form
atte
d
an
d
wh
eth
er
the
d
isk
ne
ed
s to
b
e
form
atte
d
by
th
e
co
ntro
ller
as
we
ll as
n
ee
din
g
dire
cto
ry
initia
lizatio
n.
Bit 7
of A
UX
l is
set
to
sk
ip th
e
ph
ys
ica
l fo
rm
attin
g o
f th
e
en
tire
disk
s
ur
face
w
he
n
it is
no
t re
qu
ired
, a
nd
b
its 6
-0
o
f A
UX
l a
nd
a
ll o
f A
UX
2 c
an
b
e
use
d
to
spe
cify
th
e
nu
mb
er
o
f se
cto
rs o
n
the
d
isk
be
ing
c
rea
ted
(if
all
15 b
its
are
ze
ro
, th
e
dis
k
is a
ss
um
ed
to
b
e
the
s
ize
de
fine
d
by
th
e
driv
e
co
nfig
ura
tion
).
Th
is
pe
rm
its
for
ma
tting
a
s
ing
le
side
d
dis
ke
tte
on
a
do
ub
le
sid
ed
d
riv
e,
for
ex
am
ple
.
To
lo
ad
(a
nd
p
os
sib
ly
ex
ec
ute
) a
p
rog
ram
file
, M
YD
OS
p
rov
ide
s th
e
CIO
fu
nc
tion
3
9
ca
ll. F
ro
m
BA
SIC
y
ou
c
an
lo
ad
a
nd
e
xe
cu
te
a
pr
og
ra
m
by
e
xec
utin
g
the
lin
e:
XIO
3
9,
#3
, 4, O
, "D
:MY
PR
OG
.OB
J"
An
y
ina
ctiv
e
IOC
B
ca
n
be
u
sed
, a
nd
if
AU
X1=
4
bo
th
the
IN
IT a
nd
th
e
RU
N e
ntr
ies
will
be
e
xe
cu
ted
. If AU
X1=
5, th
e
RU
N e
ntr
y w
ill b
e
exe
cu
ted
, if A
UX
1=6
, th
e
INIT
en
try
w
ill b
e e
xec
ute
d,
an
d
if A
UX
1=7
, th
e
file
will
be
lo
ad
ed
w
itho
ut e
xec
utin
g
eith
er
en
try
p
oin
t.
An
y o
the
r va
lue
s o
f AU
Xl w
ill re
tur
n a
n e
rr
or
co
de
an
d
do
n
oth
ing
.
pa
ge
16
R
ev
isio
n
4.3
a
An
oth
er
XIO
c
all,
XIO
34
, h
as
be
en
a
dd
ed
to
cre
ate
a
d
irec
tor
y.
Wh
en
a
d
irec
tor
y
is c
rea
ted
, th
e n
am
e
use
d
mu
st
no
t m
atc
h
an
y
ex
istin
g
file
or
dire
cto
ry
in
its p
are
nt
(for
ex
am
ple
if
the
d
irec
tor
y
to b
e
cre
ate
d
is n
am
ed
"D
l:TE
ST
:", the
re
can
b
e
no
oth
er
d
irec
tor
y
in
the
m
ain
d
irec
tor
y
na
me
d
"TE
ST
" n
or
a
file
n
am
ed
"T
ES
T"
the
re.
Fr
om
B
AS
IC
the
X
IO
34
c
all
is
"X
IO
34, #
ioc
b,
8, O,
dir
na
me
" w
he
re
"ioc
b"
is
an
y
av
aila
ble
u
nit
nu
mb
er,
an
d
"d
irn
am
e"
is th
e
na
me
o
f th
e
ne
w
dire
cto
ry
(it d
oes
n
ot e
nd
w
ith
a
trailin
g ':').
Th
e
fina
l fu
nc
tion
a
dd
ed
to
th
ose
p
rov
ide
d
by
AT
AR
I D
OS
2
is X
IO
41
, to
de
fine
th
e
de
fau
lt d
irec
tor
y.
Th
e
de
fau
lt d
ire
cto
ry
is
th
at
wh
ich
w
ill b
e
sea
rch
ed
fo
r a
file
if
the
file
n
am
e
be
gin
s
with
"
D:"
. In
A
TA
RI
DO
S
2 th
is
de
fau
lt d
irec
tory
is
alw
ay
s
"Dl:"
bu
t in
M
YD
OS
4
, th
P. d
efa
ult
dire
cto
ry
ca
n
be
a
ny
roo
t o
r s
ub
or
din
ate
d
irec
tor
y
on
a
ny
d
isk
in
th
e
sy
ste
m.
Th
e
bu
ffer
ad
dre
ss
p
asse
d
CIO
in
th
e X
IO
41
ca
ll is
th
e
ad
dr
es
s
of
a
str
ing
th
at
co
nta
ins
th
e
de
fau
lt d
irec
tor
y
na
me
, te
rm
ina
ted
w
ith
eith
er
an
e
nd
o
f line
($9
B)
or
a
nu
ll by
te
($00
).
Th
e
dire
cto
ry
w
ill b
e
acce
sse
d
be
fore
re
tur
nin
g
to
the
c
allin
g
pro
gra
m
so
tha
t an
er
ro
r
in
sp
ec
ifyin
g
the
d
irec
tor
y w
ill b
e
rep
orte
d
as e
arly
a
s
po
ss
ible
.
VI.
CIO
FU
NC
TIO
N
CO
DE
S
PR
OV
IDE
D
BY
M
YD
OS
4
Fun
ctio
n
co
de
3,
OP
EN
Th
e
op
en
fu
nc
tion
u
ses
th
e
bu
ffer
ad
dr
es
s
to p
oin
t to
a
n
AT
AS
CI
str
ing
te
rm
ina
ted
w
ith
a
ch
ara
cte
r n
ot
0-
9,
A-Z
, a
-z
, :,
?,
or
*
· T
his
s
trin
g
is
the
n
am
e
of
the
file
to
b
e
ac
ce
ss
ed
o
r
cre
ate
d.
A
go
od
te
rmin
ato
r fo
r th
is
str
ing
is
eith
er
a
nu
ll ($0
0)
or
an
en
d
of
line
($
9B
).
Th
e
AU
Xl
by
te
de
fine
s th
e
usa
ge
of
the
file
: 4
for
inp
ut, 6
for
dire
cto
ry
da
ta
rea
din
g,
8 fo
r c
rea
ting
/re
pla
cin
g
ou
tpu
t, 9
for
cre
atin
g/
ap
pe
nd
ing
o
utp
ut a
nd
12
for
inp
ut/
up
da
te
(with
ou
t ex
ten
sion
).
Th
e
AU
X2
b
yte
is
use
d
wh
en
a
file
is
rep
lac
ed
o
r
cre
ate
d,
an
d
co
nta
ins
th
ree
sig
nific
an
t b
its,
bit
1 se
t c
au
ses
a
DO
S
I fo
rma
t file
to b
e
cre
ate
d
if th
e
dis
ke
tte
is
sin
gle
sid
ed
, s
ing
le
de
ns
ity
(oth
er
wise
, it
is ig
no
red
). B
it 2 se
t c
au
se
s
the
M
YD
OS
fo
rma
t to
b
e u
se
d
ev
en
if
the
d
isk
ette
is a
40
tra
ck
s
ing
le
side
d
dis
ke
tte.
An
d
bit
6 se
t re
su
lts
in
the
file
b
ein
g
LO
CK
ed
in
itially
w
itho
ut a
nd
ad
ditio
na
l C
IO
ca
ll.
Fo
r in
pu
t, u
pd
ate
o
r d
irec
tory
a
cc
ess
AU
X2
is
ign
ore
d,
an
d
the
le
ng
th
is
alw
ay
s
ign
ore
d.
In
no
rm
al
use
, A
UX
2
is
set
to
ze
ro
em
ula
ting
A
TA
RI
DO
S
2 u
sag
e.
MY
DO
S
4 a
lso
do
es
no
t le
av
e
pa
rtially
fu
ll se
cto
rs
w
he
n
ap
pe
nd
ing
to
a
file
. T
his
h
as
two
e
ffec
ts o
n
pro
gra
ms
w
hic
h
op
en
file
s in
a
pp
en
d
mo
de
:
pa
ge
17
R
evisio
n
4.3a
the
o
pe
n
will
fail
if th
e
file
ca
nn
ot
be
a
pp
en
de
d
to
ra
the
r
tha
n
the
c
lose
(a
s in
A
TA
RI
DO
S),
an
d
the
file
size
w
ill n
ot
ch
an
ge
if
a
file
ap
pe
nd
ed
to
is
co
pie
d
to
an
oth
er
d
isk
(in
AT
AR
I DO
S
it m
ay
g
row
s
ma
ller
).
MY
DO
S
4.3
, u
nlik
e
ea
rlier
ve
rsion
s,
will
be
fo
rce
d
to
rere
ad
th
e
en
tire
file
wh
en
c
los
ing
it
if m
ore
th
an
o
ne
file
a
t a
time
is
o
pe
ne
d
in
ap
pe
nd
m
od
e.
Fu
nc
tion
co
de
5
, GE
T
RE
CO
RD
Th
e
ge
t re
co
rd
fun
ctio
n
rea
ds
a
lin
e
of
da
ta
into
a
b
uffe
r,
the
b
uffe
r b
ein
g
de
fine
d
by
its
sta
rting
a
dd
res
s
an
d
len
gth
. T
he
lin
e
is d
efin
ed
a
s
the
d
ata
b
yte
s
in
the
file
u
p
to
an
e
nd
o
f lin
e
ch
ara
cte
r ($
9B
) o
r u
ntil
the
b
uffe
r is
fu
ll, w
hic
he
ve
r o
cc
urs
firs
t. T
he
lin
e
is
also
te
rm
ina
ted
if
the
e
nd
o
f th
e
file
is
rea
d.
All
rec
ord
I/O
is
b
uffe
red
in
M
YD
OS
so
re
co
rd
tran
sfe
rs
are
n
ec
essa
rily
slow
er
tha
n
un
bu
ffere
d
I/O.
No
o
the
r fie
lds
of
the
IO
CB
a
re
refe
ren
ce
d
or
ne
ed
ed
. N
ote
th
at
the
A
TA
RI
RO
M
OS
s
up
po
rts
s
ing
le
by
te
I/0
th
rou
gh
th
e
ac
cu
mu
lato
r if
the
b
uffe
r le
ng
th
is
set
to
0.
In
this
c
as
e,
GE
T
RE
CO
RD
a
nd
G
ET
C
HA
RA
CT
ER
S
fun
ctio
n e
xa
ctly
th
e
sam
e w
ay
.
Fu
nc
tion
c
od
e
7,
GE
T
CHA
RAC
TE
RS
Th
e
ge
t c
ha
ra
cte
rs
fu
nc
tion
re
ad
s
a
fixe
d
nu
mb
er
o
f b
yte
s fro
m
a
file
into
a
b
uffe
r,
the
b
uffe
r b
ein
g
de
fine
d
by
its
ad
dre
ss
a
nd
le
ng
th
(two
16-
bit
nu
mb
er
in
th
e
IOC
B).
Th
e
on
ly
case
w
he
re
th
e
bu
ffer
is
no
t a
lwa
ys fille
d is
if th
e e
nd
of th
e file
is
rea
d.
As
is
the
c
ase
w
ith
ge
t re
co
rd
ca
lls,
a
sin
gle
b
yte
m
ay
b
e re
ad
in
to
the
a
cc
um
ula
tor
by
se
tting
th
e
len
gth
field
to
ze
ro
. A
g
et
ch
ara
cte
r C
IO
ca
ll w
ill b
e
pe
rform
u
nb
uffe
red
I/O
if
the
b
uffe
r is
lon
ge
r
tha
n
25
6
by
tes
(AT
AR
I D
OS
2
se
ts
a
sim
ilar
thre
sho
ld
at
128
by
tes
). F
or
th
is
rea
son
a
s
ing
le
lon
g
inp
ut is
c
on
sid
era
bly
fa
ster
tha
n
sev
era
l s
ho
rt o
ne
s.
On
ly
the
b
uffe
r a
dd
res
s
an
d
len
gth
in
th
e
IOC
B
are
u
sed
b
y
the
g
et
ch
ara
cte
rs
fu
nc
tion
.
Fu
nc
tion
c
od
e
9, P
UT
R
EC
OR
D
Th
e
pu
t re
co
rd
co
mm
an
d
will
write
a
s
ing
le
line
to
a
n
ou
tpu
t file
, th
e
line
d
efin
ed
th
e
sta
rtin
g
ad
dre
ss
of
the
b
uffe
r a
nd
eith
er
th
e
len
gth
o
f th
e
bu
ffer
if n
o
en
d
of
line
($
9B
) b
yte
s
are
e
nco
un
tere
d,
or
th
e
first
en
d
of
line
b
yte
. O
nly
th
e
bu
ffer
ad
dr
es
s
an
d
len
gth
in
th
e
IOC
B
are
u
sed
in
th
is c
om
ma
nd
.
pa
ge
18
R
ev
ision
4
.3a
Fu
nc
tion
c
ode
1
1,
PU
T
CH
AR
AC
TE
RS
Th
e p
ut
ch
ara
cte
rs
c
om
ma
nd
w
ill w
rite
the
co
nte
nts
o
f a
b
uffe
r d
efin
ed
b
y
its a
dd
re
ss
a
nd
le
ng
th
(in
the
IO
CB
), to
a
file
o
pe
ne
d
for
o
utp
ut.
Th
e e
ntire
b
uffe
r is
a
lwa
ys
writte
n
to th
e
file
un
les
s
the
wr
ite
is to
a
n
ou
tpu
t/u
pd
ate
file
a
nd
th
e
en
d
of
the
file
is re
ac
he
d
or
the
w
rite
is to
a
n
ou
tpu
t/a
pp
en
d
or
crea
te file
an
d
the
last
sec
tor
on
th
e d
isk
h
as
alrea
dy
b
ee
n
allo
cate
d.
On
ly
the
b
uffe
r a
dd
re
ss
a
nd
le
ng
th
field
s in
th
e
IOC
B a
re
u
se
d
wh
en
th
e
pu
t ch
ara
cte
r fu
nc
tion
is
c
alle
d.
Fu
nc
tion
code
12
, C
LO
SE
A
FIL
E
To
te
rm
ina
te
use
o
f a
file
(an
d
for
an
o
utp
ut
file,
to
write
th
e
inc
om
ple
te
bu
ffer
to
th
e
dis
k)
the
IO
CB
u
se
d
to a
cc
es
s
the
file
sh
ou
ld
be
clos
ed
. T
his
is d
on
e
by
se
tting
th
e
fun
ctio
n
co
de
in
th
e
IOC
B
to
12
an
d
callin
g
CIO
. Th
e c
lose
fu
nc
tion
d
oe
s n
ot
us
e a
ny
of
the
da
ta
in
the
IO
CB
for
an
y
pu
rp
ose
w
ha
tsoe
ve
r.
Fun
ctio
n c
ode
13
, R
EA
D
ST
AT
US
Th
e
rea
d
statu
s c
om
ma
nd
is
issue
d
to
an
u
no
pe
ne
d
IOC
B,
with
th
e
bu
ffer
ad
dr
es
s
tha
t of
a
file n
am
e
str
ing
. If
the
file
is
no
t pr
es
en
t th
at
er
ro
r
co
nd
ition
is
r
etu
rn
ed
, if
it is
lo
ck
ed
, th
at
er
ror
co
nd
ition
is
re
tur
ne
d;
oth
er
wis
e,
a
no
rma
l c
om
ple
tion
c
od
e
is
re
tur
ne
d.
On
ly
the
fu
nc
tion
c
od
e a
nd
th
e
bu
ffer
ad
dr
es
s
in
the
IO
CB
a
re
ne
ed
ed
.
Fun
ctio
n
co
de
3
2,
RE
NA
ME
A
F
ILE
Th
e
ren
am
e
fun
ctio
n
is
pa
ssed
a
c
ha
rac
ter
str
ing
(p
oin
ted
to
b
y
the
b
uffe
r a
dd
re
ss
in
th
e
IOC
B), a
nd
th
e
firs
t p
ar
t of
the
s
trin
g
is a
file
n
am
e
str
ing
id
en
tifyin
g
the
file
o
r file
s to
b
e
ren
am
ed
. F
ollo
win
g
a
sing
le
inv
alid
c
ha
rac
ter
(on
e
inv
alid
in
th
e
file n
am
e,
tha
t is
) a
sim
ple
file
n
am
e
mu
st a
lso
be
p
re
se
nt:
this
se
co
nd
file
n
am
e
ca
nn
ot
inc
lud
e
an
y
dr
ive
o
r d
ire
cto
ry
n
am
es.
An
e
xa
mp
le,
usin
g
a
co
mm
a a
s th
e in
va
lid
ch
ara
cte
r, is
D2
:TE
ST
:PG
MS
:A.O
UT
,ZC
PY
wh
ich
w
ill c
ha
ng
e
the
s
trin
g
ne
ed
ed
to
a
cc
es
s
the
file
"D2
:TE
ST
:PG
MS
:A.O
UT
" to
"D
2:T
ES
T:P
GM
S:Z
CP
Y"
--
No
te
tha
t o
nly
th
e la
st file
na
me
(if
su
bd
ire
cto
ries
are
u
se
d)
ca
n
be
c
ha
ng
ed
, to
c
ha
ng
e
"PG
MS
" to
"ML
PR
OG
S",
the
b
uffe
r m
us
t c
on
tain
"D
2:T
ES
T:P
GM
S,M
LP
RO
GS
" an
d th
e
ren
am
e w
ill als
o c
ha
ng
e
the
full n
am
es
of
all file
s in
"D
2:T
ES
T:P
GM
S"
(to
be
lab
or
the
ob
vio
us
).
Wild
c
ard
c
ha
rac
ter
s
sho
uld
a
pp
ea
r o
nly
in
th
e
pa
rt o
f
the
file
na
me
fo
llow
ing
th
e
last
':' a
nd
th
eir
effe
ct
is b
est
de
sc
rib
ed
b
y
an
e
xa
mp
le.
pa
ge
19
R
ev
ision
4
.3a
Th
e
str
ing
"D
2:T
ES
T:*
·*•*
·XY
Z"
will
re
na
me
a
ll th
e files
in
the
T
ES
T
dir
ec
tor
y,
ma
kin
g
ea
ch
file
's
ex
ten
sion
".X
YZ
".
If the
d
ire
cto
ry
h
ad
th
e file
s "A
TE
ST
.BA
S"
, "
LO
G",
an
d
"RE
PO
RT
.XY
Z"
in
it, th
e
re
su
lt w
ou
ld
be
a
d
ire
cto
ry
w
ith
"AT
ES
T.X
YZ
", "L
OG
.XY
Z'"
an
d
"RE
PO
RT
.XY
Z"
in
it.
Fu
nc
tion
c
od
e
33
, D
EL
ET
E
A
FIL
E
Th
e
de
lete
fu
nc
tion
re
mo
ve
s a
ny
file
s th
at
ma
tch
th
e
file
na
me
s
trin
g
po
inte
d
to
by
th
e
bu
ffer
ad
dr
es
s
in
the
IO
CB
. F
iles
loc
ke
d
will
no
t b
e
de
lete
d, s
o m
us
t b
e
un
loc
ke
d
be
fore
b
ein
g re
mo
ve
d,
an
d
dire
cto
ries
th
at
ar
e n
ot e
mp
ty
(tha
t h
av
e
a
file,
ev
en
a
n e
mp
ty
file,
in
the
m)
ca
nn
ot
be
d
ele
ted
. If
eith
er
c
as
e
is
atte
mp
ted
, th
e
co
rr
es
po
nd
ing
e
rro
r
co
de
is
r
etu
rn
ed
. O
the
rw
ise
, th
e
files
ar
e
re
mo
ve
d
an
d
the
ir
da
ta
ar
ea
s
ar
e
re
tur
ne
d to
the
fre
e s
pa
ce
on
th
e d
isk
.
Lik
e
oth
er
A
tari
DO
Ss
, in
M
YD
OS
file
s re
mo
ve
d
ca
nn
ot
be
(ea
sily
) re
co
ve
re
d
afte
r b
ein
g
de
lete
d.
Th
is
is u
nlik
e
som
e
oth
er
o
pe
ra
ting
s
ys
tem
s
tha
t p
re
se
rv
e
de
lete
d
files
fo
r
as
lo
ng
a
s p
rac
tica
l b
efo
re
ov
er
wr
iting
th
em
.
Fu
nc
tion
c
od
e
34
, MAK
E D
IRE
CT
OR
Y
Th
e m
ak
e
dir
ec
tor
y fu
nc
tion
w
ill c
re
ate
a
new
s
ub
dir
ec
tor
y
on
a
d
isk
(it
is n
ot
us
ed
to
c
rea
te
the
first d
ire
cto
ry
, th
at
is
the
"roo
t d
ire
cto
ry
" id
en
tified
b
y
the
driv
e
spe
cific
atio
n
"D
l:",
for
ex
am
ple
). It
is
ca
lled
th
ro
ug
h
CIO
b
y
sto
ring
th
e a
dd
re
ss
o
f th
e
ne
w
dir
ec
tor
y's
n
am
e
in
the
IO
CB
b
uffe
r a
dd
re
ss
a
nd
s
ettin
g
up
A
UX
l a
nd
A
UX
2
as
for
an
o
pe
n
ca
ll (se
e
Fu
nc
tion
c
od
e
3), n
orm
ally
A
UX
1=8
an
d
AU
X2
=0
.
Th
is
fun
ctio
n
ha
s
no
effec
t on
th
e c
ur
re
nt
defa
ult
dir
ec
tor
y, a
nd
if it
is d
esire
d
to
ma
ke
th
e
ne
wly
c
rea
ted
d
irec
tory
th
e
de
fau
lt o
ne
, th
e
pro
gra
m
mu
st m
ak
e
a
se
t d
irec
tor
y c
all
(Fu
nc
tion
co
de
4
1) fo
llow
ing
th
e
ma
ke
d
ire
cto
ry
c
all
(the
o
rd
er
is
ve
ry
im
po
rtan
t, b
ec
au
se
th
e
de
fau
lt d
irec
tor
y c
an
no
t b
e se
t to
a
n
on
ex
iste
nt
dir
ec
tor
y).
Fu
nc
tion
c
ode
35
, LO
CK
F
ILE
A
file
ca
n
be
"lo
ck
ed
" so
th
at
it m
ay
n
ot
be
m
od
ified
o
r d
ele
ted
in
ad
ve
rte
ntly
b
y
ca
lling
C
IO
with
th
e
loc
k
fun
ctio
n.
Th
e
bu
ffer
ad
dr
es
s
is
us
ed
to
p
oin
t to
a
file
na
me
s
trin
g
tha
t id
en
tifies
the
file
s o
n
the
d
isk
to
be
lo
ck
ed
. T
he
on
ly
file m
od
ifica
tion
th
at c
an
b
e
pe
rfor
me
d
on
a
lo
ck
ed
file
is to
u
nlo
ck
it.
Th
e lo
ck
fu
nc
tion
ca
n
be
re
qu
este
d
for
a
file a
lrea
dy
loc
ke
d,
an
d
it w
ill r
etu
rn
n
o
er
ror
(un
like
o
the
r
file
mo
dific
atio
n
ca
lls to
C
IO),
bu
t th
e
sta
tus
of th
e
file
will
no
t h
av
e
be
en
c
ha
ng
ed
e
ithe
r.
pa
ge
20
R
ev
ision
4
.3a
Fu
nc
tion
co
de
3
6,
UN
LO
CK
F
ILE
Th
e
un
loc
k
fun
ctio
n
is id
en
tical
to th
e
lo"ck
fu
nc
tion
e
xc
ep
t th
at
is re
en
ab
les
the
m
od
ifica
tion
o
r d
ele
tion
o
f a
n
un
loc
ke
d
file.
A
file
tha
t is
no
t lo
ck
ed
c
an
b
e
un
loc
ke
d
with
n
o
er
ro
r
re
tur
ne
d
an
d
no
c
ha
ng
e
in
the
file's
s
tatu
s.
Fu
nc
tion
c
ode
37
, P
OIN
T T
O P
OS
ITIO
N
IN
FIL
E
Th
e
po
int
fun
ctio
n
is
pa
ssed
th
e
3-
by
te d
isk
ad
dr
es
s
to
be
p
ositio
ne
d
to
in
the
tw
elfth
th
rou
gh
fo
ur
tee
nth
b
yte
s o
f th
e
IOC
B.
On
r
etu
rn
, th
e
ne
xt
by
te re
ad
fro
m
tha
t IO
CB
w
ill b
e
the
o
ne
th
at
wa
s re
ad
o
r w
ritten
n
ex
t afte
r th
e c
or
re
sp
on
din
g
no
te fu
nc
tion
w
as
e
xec
ute
d.
A
po
int c
all
to C
IO c
an
o
nly
be
ma
de
if
the
file
ca
n
be u
se
d
for in
pu
t: th
at
is,
if it
is
op
en
ed
fo
r in
pu
t o
r u
pd
ate
p
roc
es
sin
g.
Th
e
firs
t tw
o
by
tes
o
f th
e
dis
k
ad
dr
es
s
are
a
s
ec
tor
nu
mb
er
(in
lo
w
by
te/
hig
h
by
te
form
at)
an
d
the
th
ird
is
the
b
yte
w
ithin
th
e
sec
tor.
If a
file
is
be
ing
a
pp
en
de
d
to
(op
en
ed
w
ith
AU
X1=
9),
a
po
int
fun
ctio
n
call
ma
de
b
efo
re
clo
sin
g
the
file
ma
y
re
tur
n
an
u
ne
xp
ec
ted
e
rr
or
(th
is
ca
nn
ot
ha
pp
en
with
th
e
no
te
fun
ctio
n,
ho
we
ve
r).
A
pro
ble
m
ca
n
oc
cu
r
if th
e
file b
ein
g
po
inte
d
to is
in
the
last
ha
lf of
a
16 M
eg
ab
yte
d
isk
: A
tari
BA
SIC
s
do
n
ot
allo
w
sec
tor
nu
mb
er
to
b
e g
rea
ter
tha
n
32
76
7.
A
solu
tion
is
to
use
the
follo
win
g
six lin
e s
ub
stitute
fo
r th
e
PO
INT
s
tate
me
nt
(with
a
tten
tion
pa
id
to
the
fac
t the
th
e
two
A
UX
b
yte
s
mu
st m
atc
h
the
tw
o
use
d
to
op
en
th
e file
):
OP
EN
#
K,A
UX
1,AU
X2
, "D5
:BIG
FIL
E"
NO
TE
#
K,S
EC
TO
R,P
OS
ITIO
N
HIG
HB
YT
E
= IN
T(S
EC
TO
R/
25
6)
LO
WB
YT
E
= S
EC
TO
R
-H
IGH
BY
TE
*25
6
PO
KE
84
4+
16*K
,LO
WB
YT
E
PO
KE
8
45
+16
*K,H
IGH
BY
TE
P
OK
E
846
+ 16
*K,P
OS
ITIO
N
XIO
37
,#K
,AU
X1,A
UX
2,"
"
Fu
nctio
n
code
3
8,
NO
TE
P
OS
ITIO
N
IN
FIL
E
Th
e
no
te
fun
ctio
n
re
tur
ns
in
th
e
twe
lfth
thro
ug
h
fou
rte
en
th
by
tes
of
the
IOC
B
a
3-
by
te d
isk
a
dd
re
ss
th
at
ma
y
be
u
se
d
at
a
later
time
to
re
po
sition
the
file u
sing
th
e
po
int
fun
ctio
n.
Th
e
no
te
fun
ctio
n
can
b
e u
se
d o
n file
s o
pe
n
for
inp
ut, o
utp
ut,
up
da
te
or
ap
pe
nd
ing
.
Th
e
three
by
tes
r
etu
rn
ed
a
re
the
lo
w
by
te
of
the
se
cto
r a
dd
re
ss
, th
e
hig
h
by
te o
f th
e
sec
tor
ad
dr
es
s,
an
d
the
b
yte
with
in
the
s
ec
tor
in
tha
t o
rd
er.
pa
ge
2
1 R
ev
isio
n 4.3a
Fu
nc
tion
co
de
39
, L
OA
D
ME
MO
RY
Th
e lo
ad
m
em
or
y
fun
ctio
n
tak
es
a
file
for
ma
tted
in
th
e A
TA
RI
DO
S
2 e
xe
cu
tab
le
pro
gra
m
form
at
(ge
ne
ra
ted
b
y
the
"K"
co
mm
an
d,
by
th
e
as
se
mb
ler
/e
dito
r c
artrid
ge
, b
y
AM
AC
o
r M
AC
65
, o
r b
y
an
y
of
se
ve
ral
co
mp
iler
s
for
the
A
TA
RI
co
mp
ute
rs
) a
nd
lo
ad
s
its c
on
ten
ts
into
th
e
co
mp
ute
r's
m
em
or
y
as
sp
ec
ified
in
th
e file
.
No
o
ffset
co
ntro
l is
pro
vid
ed
a
nd
n
o
pa
rt o
f m
em
ory
is
pr
ote
cte
d
from
th
e
loa
din
g
pro
ce
ss
. T
he
in
itializa
tion
a
nd
e
xe
cu
tion
a
dd
re
ss
es
(if
an
y)
can
b
e
ind
ivid
ua
lly
en
ab
led
a
nd
d
isa
ble
d,
ho
we
ve
r,
to
pe
rm
it lo
ad
ing
an
d
pa
tch
ing
a
pro
gra
m
the
n
wr
iting
it
ba
ck
to
the
d
isk
fo
r n
or
ma
l us
e.
To
lo
ad
a
p
rog
ram
in
to
me
mo
ry
, th
e
ad
dr
es
s
of
the
file
n
am
e
str
ing
is
sto
red
in
to
the
b
uffe
r a
dd
re
ss
an
d
a
va
lue
o
f 4, 5
, 6 o
r 7
is s
tor
ed
into
th
e A
UX
l fie
ld.
If A
UX
l is
4, b
oth
th
e in
itializa
tion
ro
utin
es
an
d
the
ru
n
ad
dr
es
s
ar
e
ex
ec
ute
d
afte
r c
losin
g
the
IO
CB
u
se
d
bu
t be
for
e
re
tur
nin
g
to th
e c
allin
g
pr
og
ra
m.
If A
UX
l is
5,
the
in
itializa
tion
r
ou
tine
s
ar
e
dis
ab
led
, b
ut
the
p
ro
gr
am
w
ill b
e
ru
n.
If A
UX
l is
6,
the
in
itializa
tion
r
ou
tine
s
will
be
r
un
, b
ut
the
p
rog
ram
e
xe
cu
te
ad
dr
es
s
will
be
lo
ad
ed
a
nd
ig
no
red
. If
AU
Xl
is 7
, th
e
tex
t o
f th
e
pr
og
ra
m
will
be
lo
ad
ed
in
to
me
mo
ry
, b
ut
no
o
the
r a
ctiv
ity
will
be
p
erfo
rm
ed
.
Fu
nc
tion
c
od
e 4
1, S
ET
D
EF
AU
LT
D
IRE
CT
OR
Y
Th
e
set d
ire
cto
ry
c
om
ma
nd
w
ill u
se th
e c
on
ten
ts o
f th
e b
uffe
r a
s a
file
na
me
an
d
op
en
the
sp
ec
ified
file
, d
ete
rm
inin
g
if th
at
file
is
a
va
lid
dir
ec
tor
y.
If so,
it w
ill b
ec
om
e
the
n
ew
d
efa
ult
dir
ec
tor
y.
Th
at
is, file
n
am
es
of
the
fo
rm
"D: ... "
will
be
a
ss
um
ed
to
b
e
in
the
d
efa
ult
dir
ec
tor
y
(wh
ich
m
ay
b
e
on
a
ny
d
isk
in
th
e
sy
ste
m
an
d
ma
y
be
e
ithe
r
the
ro
ot
dir
ec
tor
y o
f th
at
dis
k o
r a
su
bd
irec
tor
y).
On
ly
the
b
uffer
ad
dr
es
s
an
d
the
fu
nc
tion
c
od
e
are
s
ign
ifica
nt
wh
en
s
ettin
g
the
d
efa
ult
dir
ec
tor
y.
Fu
nc
tion
c
od
e
25
4,
FO
RM
AT
A
D
ISK
ET
TE
Th
e
form
at
fun
ctio
n
us
es
th
e
co
nte
nts
o
f th
e b
uffe
r p
oin
ted
to
b
y
the
b
uffe
r a
dd
re
ss
to
id
en
tify
the
d
rive
c
on
tain
ing
th
e
dis
ke
tte
to
be
fo
rma
tted
. If
bo
th
AU
Xl
an
d
AU
X2
a
re
ze
ro
, th
e
dis
k
is fo
rm
atte
d
ac
co
rd
ing
to th
e
ca
pa
city
d
ata
in
the
s
ys
tem
c
on
trol
tab
le
de
fine
d
us
ing
th
e
'O'
com
ma
nd
. If
AU
X2
b
it 7
is
se
t to
1
, th
e
form
at
op
era
tion
is
sk
ipp
ed
a
nd
a
n
em
pty
file
s
ys
tem
is
wr
itten
to
th
e
dis
ke
tte.
!Th
is
as
su
me
s
the
d
isk
is
p
refo
rma
tted
.)
Th
e
re
ma
inin
g
15 b
its o
f AU
Xl
an
d
AU
X2
a
re
u
se
d a
s a
15
bit
nu
mb
er
to
sp
ec
ify
the
n
um
be
r
of
sec
tors
av
aila
ble
on
th
e
dis
k
(pe
rm
itting
th
e
us
e
of
the
la
st fe
w se
cto
rs
of a
d
isk
ou
tsid
e
the
file
sy
ste
m if
de
sire
d),
pa
ge
22
R
ev
isio
n
4.3a
VII.
DIS
K
ST
RU
CT
UR
ES
S
UP
PO
RT
ING
M
YD
OS
4
MY
DO
S
4 u
se
s
the
fir
st
thr
ee
se
cto
rs o
f a
d
isk
to
h
old
so
me
dis
k
info
rm
atio
n
an
d
the
in
itial
bo
ot
pro
gra
m
if th
e
driv
e
co
nta
ins
DO
S.S
YS
a
nd
D
UP
.SY
S.
Se
cto
r
$16
8 (a
nd
s
ec
tor
s
$16
7,
$16
6,
$16
5,
etc.,
if th
e
dis
k
is
form
atte
d
as
a
hig
he
r c
ap
ac
ity
disk
n
ot
co
mp
atib
le
with
A
TA
RI
DO
S
2) is
us
ed
to
h
old
a
b
it m
ap
o
f a
va
ilab
le
se
cto
rs
a
nd
se
ve
ral
flag
b
yte
s
ide
ntify
ing
th
e
de
fau
lt fo
rma
t of
files
on
th
e d
isk
.
Se
cto
rs
$16
9 th
rou
gh
$
170 c
on
tain
m
ain
d
isk
d
irec
tory
d
ata
, id
en
tifyin
g
the
files
on
th
e
dis
k,
the
ir
size
s
an
d
the
ir
startin
g s
ec
tor
nu
mb
er
.
No
te th
at
this
u
sa
ge
, w
he
n
the
d
isk
ette
is
a
7
19
sec
tor
vo
lum
e
de
cla
re
d
to
be
D
OS
2
co
mp
atib
le,
is
in
fac
t ex
ac
tly
the
s
am
e
as
A
TA
RI
DO
S
2 w
ou
ld
ma
ke
of
the
d
isk
. T
he
de
fau
lt sin
gle
sid
ed
fo
rm
at
diffe
rs
on
ly
in
tha
t s
ec
tor
720
is
no
t le
ft o
ut
of
the
file
sy
stem
in
M
YD
OS
b
ut
is u
se
d
to p
rov
ide
70
8 fr
ee
se
cto
rs
in a
n e
mp
ty d
isk
ette
ra
the
r th
an
7
07
.
Th
e
ch
an
ge
s
ma
de
wh
en
th
e
hig
h
cap
ac
ity
form
at
is
ch
os
en
a
re
to
a
lloc
ate
e
no
ug
h
se
cto
rs
b
efo
re
se
cto
r $
168
to
as
sig
n
a
bit
for
eac
h
se
cto
r
tha
t m
ay
b
e
allo
ca
ted
fo
r a
file
or
fo
r u
se b
y
the
s
ys
tem
. T
he
h
igh
c
ap
ac
ity
dis
k
dir
ec
tor
y
ma
y b
e re
ad
b
y
AT
AR
I D
OS
2
, b
ut
the
d
ata
in
th
e files
ca
n
on
ly
be
a
cc
es
se
d
if it fa
lls in
th
e fir
st
102
3
se
cto
rs
o
f th
e
dis
k
an
d
the
n
on
ly
if th
e file
nu
mb
er
c
he
ck
ing
co
de
in
DO
S
2 is
disa
ble
d.
Th
is
form
at
an
d
MY
DO
S
4 s
up
po
rt
ac
ce
ss
ing
d
isk
s
of
up
to
6
5,5
35
s
ec
tor
s o
f 25
6
by
tes
ea
ch
(a
pp
rox
ima
tely
16
Mb
yte
s).
Co
mp
atib
ility
with
A
tari
DO
Ss
is
fu
rth
er
r
ed
uc
ed
if
s
ub
dir
ec
tor
ies
a
re
u
sed
: to
AT
AR
I DO
S
2.0
, th
e
su
bd
ire
cto
ries
will
ap
pe
ar
to
be
s
imp
le
files
w
ith
un
rea
da
ble
c
on
ten
ts.
Th
e
su
bd
ire
cto
ry
's file
s w
ill n
ot
be
ac
ce
ssib
le
an
d
the
s
ub
dir
ecto
ry
c
an
b
e
da
ma
ge
d
if it
is
writte
n
to
(ev
en
b
y
ap
pe
nd
ing
). F
or
this
r
ea
so
n
dis
ks
so
ld
to
the
g
en
era
l p
ub
lic,
ex
ch
an
ge
d
with
frie
nd
s,
an
d
so
for
th,
sh
ou
ld
no
t c
on
tain
s
ub
dir
ec
tor
ies
u
nle
ss
th
er
e
is re
aso
n
to
re
qu
ire
th
at
the
d
isk
b
e
us
ed
w
ith
MY
DO
S.
A
fur
the
r
pr
ob
lem
w
ith
exc
ha
ng
ing
d
isk
ette
s
is th
at
the
re
a
re
m
an
y
diffe
re
nt fo
rm
ats
ar
e
us
ed
b
y
ve
nd
or
s o
f d
ou
ble
sid
ed
d
isk
s
ys
tem
s
for
the
AT
AR
I. F
or
this
re
aso
n,
do
ub
le
sided
d
isk
s
no
t o
nly
r
eq
uir
e
bo
th
co
mp
ute
rs
u
se M
YD
OS
, b
ut
also
r
eq
uir
e
tha
t th
ey
u
se th
e sa
me
dis
k
sy
ste
m
(PE
RC
OM
, S
WP
, As
tra
, Su
pr
a o
r w
ha
tev
er
).
VIII.
MYD
OS
4
M
EM
OR
Y
MAP
Th
e M
YD
OS
4
.3
dis
k
op
era
ting
s
ys
tem
o
cc
up
ies
the
area
fro
m
$0
700
to
$
1EE
E
at
all
time
s,
an
d
wh
en
th
e m
enu
is
a
ctiv
e,
it a
lso
oc
cu
pie
s
the
a
re
a fr
om
$1E
EE
to
$4
0F
F.
In a
dd
ition
, th
e
first
16 b
yte
s
of
the
flo
atin
g
po
int w
or
ks
pa
ce
($
D4
-$
E3
) a
re
u
se
d
by
M
YD
OS
4
at
tha
t tim
e.
Un
like
pa
ge
23
R
ev
isio
n
4.3
a
AT
AR
I D
OS
2,
MY
DO
S
4 u
tility
pr
og
ra
m
fDU
P.S
YS
l a
lso
ca
lls th
e
floa
ting
p
oin
t RO
M e
ntr
y
po
ints
.
Th
e
no
nr
es
ide
nt
pa
rt
of
MY
DO
S
4.3
s
tar
ts
loa
din
g
at
$2
6E
E,
re
se
rv
ing
th
e a
re
a fr
om
$
1EE
E
to
$2
6E
E
for
d
isk
b
uffe
rs a
nd
d
riv
er
s.
Allo
ca
ting
th
re
e
dis
k
bu
ffer
s
lea
ve
s
ex
ac
tly
20
48
b
yte
s
for
r
es
ide
nt
dr
ive
rs
th
at
will n
ot
be
ov
er
wr
itten
b
y
the
n
on
re
sid
en
t p
ortio
n
of
DO
S
(co
nta
ine
d
in
DU
P.S
YS
).
IX.
CU
ST
OM
IZIN
G A
S
YS
TE
M
DIS
K
Cu
sto
m
RAM
dis
k
Co
nf
igu
ra
tion
s
Th
e
RA
Md
isk
d
rive
r
inc
lud
ed
in
M
YD
OS
4
.3
is c
on
figu
re
d
au
tom
atic
ally
fo
r th
e
Ata
ri 130
XE
c
om
pu
ter
an
d
use
s its
b
an
ke
d
64K
b
an
k
of
me
mo
n·
for
the
RA
Md
isk
p
rov
idin
g
499 free
(sin
gle
d
en
sity
, 128
by
te)
se
cto
rs
. T
he
'O
' c
om
ma
nd
p
ro
vid
es
a
n
ea
sy
w
ay
to
a
lter
the
o
pe
ra
tion
o
f th
e
RA
Md
isk
d
riv
er fo
r o
the
r
co
mm
on
ba
nk
ed
me
mo
ry
sy
ste
ms
. M
os
t for
th
e
80
0X
L a
nd
130
XE
u
se
th
e s
am
e
ma
pp
ing
ad
dr
es
s
(the
P
OR
TB
p
ins
of
the
P
IA
ch
ip
in
the
c
om
pu
ter
). A
128
K
RA
Md
isk
c
an
b
e
use
d
in
an
A
tar
i 13
0X
E
us
ing
th
e
las
t u
nu
se
d
pin
of
tha
t p
ort
with
n
o
trad
eo
ff (se
lec
ting
th
e
64
K
ba
nk
is
d
on
e
with
b
it 6
of
the
b
yte
wr
itten
). If
yo
u
ha
ve
s
uc
h
a
sy
ste
m, e
nte
r a
'2
' for
the
pa
ge
se
qu
en
ce
, an
d
re
tur
n fo
r th
e o
the
rs
.
If, in
stea
d
of
ad
din
g
on
e
or
two
r
ow
s
of
64
K
me
mo
ry
c
hip
s,
the
e
nh
an
ce
me
nt r
ep
lac
es
th
e
en
tire
m
em
or
y
of
the
c
om
pu
ter
w
ith
a
sin
gle
b
an
k o
f 2
56
K
me
mo
ry
c
hip
s,
the
n
the
b
an
ke
d
me
mo
ry
is
a
tota
l o
f 19
2K
a
nd
4
bits
of
the
po
rt
mu
st
be
us
ed
to
sele
ct
the
m
em
or
y
ba
nk
. O
ften
th
e
bits
u
se
d
are
bits
0
an
d
1 (a
s
in
the
130X
E)
alo
ng
w
ith
bit
6 (a
s
in
the
e
xp
an
sion
a
bo
ve
) a
nd
b
it 5
(us
ed
in
th
e 130
XE
to
c
on
tro
l b
an
kin
g
sc
re
en
m
em
or
y).
Pr
og
ra
ms
th
at
ba
nk
s
cr
ee
n
me
mo
ry
(a
v
er
y
od
d
pro
po
sition
b
ec
au
se
of
the
d
ifficu
lty
of
ob
tain
ing
a
us
efu
l s
ha
rin
g
of
the
b
an
ke
d
me
mo
ry
p
ag
e
bits
b
etw
ee
n
the
s
cr
ee
n
me
mo
ry
a
nd
th
e
pr
og
ram
) w
ill n
ot
wo
rk
with
th
is e
nh
an
ce
me
nt.
Th
is is
the
ap
pro
ac
h
us
ed
in
th
e N
ew
ell In
du
strie
s
25
6K
up
gra
de
for
th
e
Ata
ri 8
00
XL
.
If th
e
en
ha
nc
em
en
t is
d
on
e
ex
ter
na
lly
or
to
an
A
tar
i 800
(with
its
in
ter
na
l e
xp
an
sion
slo
ts),
a
ne
w
de
dic
ate
d
re
gis
ter
m
ay
b
e
us
ed
to
m
ap
th
e
16K
p
ag
es
. T
he
A
xio
n
RA
MP
OW
ER
12
8
ca
rd
for
the
A
tari
80
0
wo
rk
s
this
wa
y.
In
s uc
h
a
sy
ste
m,
the
p
ag
es
ar
e
sele
cte
d
by
w
ritin
g
a
pa
ge
n
um
be
r
to
the
m
ap
pin
g
ad
dr
es
s
an
d
no
s
ha
rin
g
of
the
8
bit
by
te
is
ne
ce
ss
ar
y.
Th
e
ad
dre
ss
o
f th
e
ma
pp
ing
r
eg
iste
r
is
en
ter
ed
e
xp
licitly
a
nd
p
ag
e
se
qu
en
ce
'5'
is a
p
ro
pe
r
se
qu
en
ce
.
Th
e
pa
ge
se
qu
en
ce
ta
ble
s
co
de
d
into
M
YD
OS
4.3
are
a
ctu
ally
on
e
64
by
te
se
qu
en
ce
ta
ble
w
ith
3 p
osib
le
pe
rm
uta
tion
s
of
the
fir
st
16
en
trie
s.
A
on
e d
igit
se
qu
en
ce
n
um
be
r
sp
ec
ifies
on
e o
f th
e fo
llow
ing
s
eq
ue
nc
es
:
pa
ge
24
Re
visio
n
4.3a
Se
q. N
o.
Pa
ge
V
alu
es
O
R
Va
lue
0
E3
, E
7,
EB
, E
F,
C3
, C
7, C
B,
CF
, S
3,
S7
, SB
, S
F, A
3,
A7
, A
B, A
F
00
C
3,
C7
, CB
, C
F, S
3,
S7
, SB
, SF
, E
3,
E7
, EB
, E
F, A
3,
A7
, AB
, AF
0
0
2 A
3, A
7, A
B, A
F,
C3
, C
7, C
B, C
F,
E3
, E
7,
DB
, D
F,
SJ
, S7
, SB
, SF
0
0
3 o
r 4
00, 0
1, 02
, 0
3,
04
, 05
, 0
6,
07
' OS,
09
, OA
, O
B,
OC
, O
D, O
E, O
F
FF
As
an
e
xa
mp
le,
yo
u
wa
nt
to
us
e
BA
SIC
/X
E
an
d
yo
u
wa
nt
to
us
e
pa
ge
s E
3, E
7,
EB
, a
nd
E
F
from
B
AS
IC
in
the
ex
ten
de
d
mo
de
an
d
pa
ge
s S
3,
S7
, S
B,
SF
, C
3,
C7
, C
B
an
d
CF
a
s a
12
SK
R
AM
dis
k.
Se
lec
ting
12
S
as
th
e
RA
Md
isk
s
ize
an
d
en
ter
ing
e
ithe
r of th
e fo
llow
ing
lin
es
--
or
C3
,C7
,CB
,CF
,83
,87
,8B
,8F
,O
sill c
on
figu
re
th
e R
AM
dis
k
to
use
on
ly
tha
t p
art
of
the
ba
nk
ed
m
em
or
y
no
t u
se
d
by
B
AS
IC/
XE
.
Th
e file
R
AM
BO
OT
.AU
T,
the
A
tar
i AM
AC
a
ss
em
ble
r
sou
rce
c
od
e fo
r
wh
ich
is
in
th
e
file
RA
MB
OO
T.M
AC
, is
a
n
AU
TO
RU
N.S
YS
file
th
at
sim
ula
tes
th
e
op
era
tion
of A
tari
DO
S
2.5
an
d
its
RA
Md
isk
.
It "fo
rm
ats
" th
e
RA
Md
isk
a
nd
co
pie
s D
UP
.SY
S
to
it, th
en
it
se
ts
the
R
AM
dis
k
un
it n
um
be
r
an
d
the
u
nit
us
ed
to
a
cc
es
s
the
D
UP
.SY
S
an
d
ME
M.S
AV
file
s to
the
un
it se
lec
ted
fo
r th
e
RA
Md
isk
.
By
m
od
ifyin
g
the
co
de
in
the
so
urc
e
file
an
d
cre
atin
g
a
mo
difie
d
AU
TO
RU
N.S
YS
file
, th
e d
riv
e u
sed
to
sa
ve
M
EM
.SA
V
an
d
fetc
h
DU
P.S
YS
c
an
b
e
mo
difie
d,
oth
er
file
s th
an
ju
st
DU
P.S
YS
c
an
b
e
co
pie
d
to
the
R
AM
dis
k
wh
en
th
e
sy
ste
m
is b
oote
d
or
an
y
oth
er
o
pe
ratio
n
cou
ld
be
p
er
for
me
d
tha
t y
ou
find
use
ful.
Nu
mb
er
o
f F
iles
Ope
n
at O
nc
e
Th
e
nu
mb
er
o
f file
s th
at
ma
y
be
sim
ulta
ne
ou
sly
o
pe
n
is se
t w
ith
the
sa
me
b
yte
a
s
in
AT
AR
I D
OS
2
: lo
catio
n
$070
9
(de
cim
al
180
1).
Th
is
by
te
co
nta
ins
a
n
um
be
r
from
0
to
16
se
tting
th
e
nu
mb
er
of
disk
file
s th
at
ma
y
be
o
pe
n
at
the
sa
me
tim
e.
No
rma
lly
it is
se
t to
3,
the
s
ma
llest
nu
mb
er
th
at
su
pp
orts
all
the
fu
nc
tion
s in
th
e
MY
DO
S
4 m
en
u.
Sp
ec
ifica
lly,
a
co
py
fro
m
on
e
dis
k
file to
a
no
the
r
req
uire
s th
ree
o
pe
n
dis
k
files
. T
he
v
alu
e
in
the
d
istr
ibu
ted
v
er
sion
of M
YD
OS
4
is
thre
e,
to
pe
rm
it m
ore
o
r fe
we
r file
s, u
se
th
e
"O"
co
mm
an
d
follo
wed
b
y
a
RE
TU
RN
.
To
p
er
ma
ne
ntly
c
ha
ng
e
the
m
ax
imu
m
nu
mb
er
o
f file
s,
us
e
the
'H
' c
om
ma
nd
to
w
rite
a
mo
difie
d
MY
DO
S
4 s
ys
tem
to
a
d
isk
.
pa
ge
2
5 R
ev
ision
4
.3a
Ea
ch
file
tha
t m
ay
b
e o
pe
n
at
on
e tim
e r
eq
uire
s
the
allo
ca
tion
o
f a
2
56
b
yte
b
uffe
r so
s
ettin
g
this
va
lue
to 7
(ins
tea
d
of
31
will c
au
se
MY
DO
S
4 to
b
e 10
24
b
yte
s
lon
ge
r
tha
n
be
fore
a
nd
th
e
pr
og
ra
ms
lo
ad
ed
m
us
t b
eg
in
no
low
er
th
an
$
22
6C
(in
ste
ad
o
f $
1E6
C).
In c
or
re
sp
on
din
g
fas
hio
n,
by
s
ettin
g
the
v
alu
e
to
1, a
B
BS
p
rog
ram
c
an
b
e
loa
de
d
in
with
5
12
by
tes
of
ad
ditio
na
l m
em
or
y
if o
nly
on
e
dis
k
file
is e
ve
r o
pe
n a
t on
e
time
(c
om
mo
nly
tr
ue
o
f b
ulle
tin
bo
ard
p
rog
ram
s).
Con
trollin
g t
he
Dis
k
Dr
ive
s
Ac
ce
sse
d
by
M
YD
OS
4
Lik
e
AT
AR
I D
OS
2,
MY
DO
S
4 a
uto
ma
tica
lly
ide
ntifie
s th
e
dis
k
dr
ive
s th
at
ar
e
pre
sen
t w
he
n
bo
ote
d
up
in
itially
a
nd
a
ny
tim
e
it is
re
initia
lized
(so
me
p
ro
gr
am
s
do
th
is
on
e
xitin
g
to
the
D
OS
a
nd
it
is a
lwa
ys
do
ne
if
the
RE
SE
T
key
is
pr
es
se
d.
MY
DO
S
4 is
dis
trib
ute
d
with
d
riv
es
1 a
nd
2
co
nfig
ur
ed
, a
ll o
the
rs
a
re o
mitte
d
in
or
de
r
to
spe
ed
u
p
the
b
ootin
g
pro
ce
ss
. T
o
mo
dify
th
e
ma
xim
um
c
on
figu
ratio
n
MY
DO
S
4 w
ill u
se,
inv
ok
e
the
'O
' c
om
ma
nd
fo
r ea
ch
d
rive
to
b
e
ad
de
d
to
!or
r
em
ov
ed
fro
m)
the
s
ys
tem
. P
re
ss
ing
th
e
RE
SE
T
ke
y w
ill th
en
u
se th
is
va
lue
to
re
de
fine
th
e
sy
ste
m.
To
p
er
ma
ne
ntly
ch
an
ge
th
e
ma
xim
um
d
rive
c
on
figu
ratio
n, u
se
th
e
'H'
co
mm
an
d, w
riting
a
ne
w c
op
y o
f M
YD
OS
4
ba
ck
to
th
e
sy
ste
m
dis
k.
Se
lec
ting
or
Dis
ab
ling
W
rite
-w
ith-
Ve
rif
y
MY
DO
S
4 is
dis
trib
ute
d
with
a
ll d
ata
w
ritten
to
th
e d
isk
re
ad
b
ack
to
v
erify
th
at
it w
as
no
t o
nly
w
ritte
n
to
the
dis
ke
tte
co
rr
ec
tly,
bu
t th
at
the
re
w
as
no
t a
p
ro
ble
m
(du
st,
a
scra
tch
in
th
e
ox
ide
c
oa
ting
, o
r so
me
o
the
r
pr
ob
lem
th
at
ma
y
ha
ve
a
risen
sin
ce
th
e
dis
ke
tte
wa
s
for
ma
tted
) th
at
pr
ev
en
ted
th
e
da
ta
from
b
ein
g
read
b
ac
k
from
th
e
dis
ke
tte.
If the
p
rog
ram
s b
ein
g
ru
n
ha
ve
n
o
lon
g
ter
m
va
lue
(g
am
es
fo
r
ex
am
ple
, o
ften
w
rite
da
ily
hig
h
sco
res
to
the
d
isk
, a
nd
lo
ss
o
f su
ch
d
ata
m
igh
t re
sult
in a
fe
w
scre
am
s o
r
mo
an
s,
bu
t so
d
oe
s w
aitin
g fo
r a
s
low
u
pd
ate
of
the
sc
ore
s afte
r e
ac
h
ga
me
!).
Th
e
by
te a
t lo
ca
tion
$
07
79
(19
13 d
ec
ima
l) c
on
trols
all
wr
ite
op
era
tion
s to
the
d
isk
. If
the
v
alu
e
'po
ke
d'
into
it is
$5
7
(87
de
cim
al),
tha
n
all
write
s
will
be
re
ad
b
ac
k
to
ve
rify
the
a
ctio
n
wa
s
su
cc
es
sfu
l. If
the
v
alu
e
'po
ke
d'
into
$
07
79
is
$5
0
(80
d
ec
ima
l) th
en
w
rites
will
be
a
ss
um
ed
s
uc
ce
ss
ful,
an
d
will
be
p
er
for
me
d
in
ab
ou
t o
ne
th
ird
th
e
us
ua
l tim
e.
No
te th
at
this
a
dd
re
ss
is
no
t th
e
sam
e
as
in
MY
DO
S
4.0
an
d
4.1 (w
he
re
it
wa
s $0
770 o
r 190
4 d
ec
ima
l).
Th
is
by
te is
d
efin
ed
, a
lon
g w
ith
the
co
un
t o
f th
e
nu
mb
er
of
bu
ffers
to
be
a
lloc
ate
d
wh
en
th
e
file
ma
na
ge
r is
initia
lized
, w
he
ne
ve
r
the
'O
' c
om
ma
nd
is
inv
ok
ed
w
ith
no
d
rive
sp
ec
ified
(o
nly
a
R
ET
UR
N
is e
nte
re
d
in
re
sp
on
se
to
th
e
driv
e
nu
mb
er
q
ue
ry
). T
o
pe
rm
an
en
tly
alte
r
it, re
write
MY
DO
S
ba
ck
to
th
e
dis
k
us
ing
th
e
'H'
co
mm
an
d
afte
r
ch
an
gin
g
it.
Th
e
ov
er
hea
d
as
soc
iate
d
with
h
an
dlin
g
lar
ge
R
AM
dis
ks
a
nd
h
ar
d
dis
ks
r
es
ult in
M
YD
OS
4
be
ing
so
me
wh
at
slo
we
r
tha
n
MY
DO
S
3 (a
nd
A
tar
i D
OS
2
) w
he
n
wr
iting
to
th
e
dis
k
wh
eth
er
v
erify
is
en
ab
led
o
r n
ot.
Th
e
timin
g
of
dis
k
I/O
to
pe
rm
it m
ax
imu
m
tran
sfer
sp
ee
d
is v
er
y c
ritic
al a
nd
pa
ge
26
R
e,·isio
n
4.3a
MY
DO
S
4 is
ab
ou
t 0
.00
15
sec
on
ds
(p
er
se
cto
r tr
an
sfe
red
) slo
we
r
tha
n
MY
DO
S
3 (w
hic
h
tak
es
a
bo
ut
0.1
sec
on
ds
). W
ith
the
s
tan
da
rd
sec
tor
inte
rlea
ve
u
sed
by
m
ost
Ata
ri c
om
pa
tible
d
riv
es
, th
is ad
ds
a
no
the
r
0.2
s
eco
nd
s to
eac
h
wr
ite o
pe
ratio
n.
X.
DIS
K
DR
IVE
IN
TE
RF
AC
E
(via
SIO
)
Th
e
ph
ys
ica
l d
isk
d
rive
s
an
d
dis
ke
ttes
a
re
e
xte
rn
al
to
the
A
TA
RI
ho
me
c
om
pu
ter
s a
nd
th
e o
ne
s
su
pp
orte
d
by
MY
DO
S
4 a
re
n
orm
ally
a
ttac
he
d
to
the
"
se
rial
inte
rfa
ce
c
on
ne
cto
r"
on
th
e
rig
ht
sid
e
or
ba
ck
o
f th
e
co
mp
ute
r.
Hig
h c
ap
ac
ity o
r
"ha
rd
" d
isk
s m
ay
als
o b
e c
on
ne
cte
d
to
the
p
ara
llel
po
rt o
f 80
0X
L a
nd
13
0X
E
co
mp
ute
rs
. T
he
so
ftwa
re
in
the
o
pe
ratin
g
sy
ste
m
(OS
R
OM
s)
to
ac
ce
ss
th
e
de
vic
es
a
ttac
he
d
to
eith
er
c
on
nec
tor
is
call
the
"
ser
ial I/
O
driv
er
" or
S
IO fo
r s
ho
rt.
Th
e M
YD
OS
4
dis
k
op
er
atin
g s
ys
tem
u
se
s
this
lo
we
r lev
el
driv
er
to
p
as
s
all
co
mm
an
ds
a
nd
in
form
atio
n
to
an
d
from
th
e
ph
ysic
al
dis
k
driv
e.
Se
ve
ral
co
mm
an
ds
w
er
e
de
fine
d
by
A
TA
RI
to
co
mm
un
ica
te
with
th
e
810
d
isk
driv
e
an
d
mo
st
ve
nd
or
s
of h
igh
p
er
for
ma
nc
e
dis
k
sy
ste
ms
fo
r th
e
Ata
ri h
av
e
ad
op
ted
a
slig
htly
e
xte
nd
ed
v
er
sion
o
f th
is
se
t of
co
mm
an
ds
. M
YD
OS
4
will
op
er
ate
in
a
lim
ited
fa
sh
ion
w
ith
an
y
dis
k
sy
ste
m
tha
t s
up
po
rts
th
e
en
tire
o
rigin
al
810
s
et,
bu
t th
e
full
se
t o
f c
om
ma
nd
s
is
re
qu
ire
d
to
su
pp
or
t all
the
fun
ctio
ns
.
An
a
dd
ition
al
fun
ctio
n
ne
ce
ss
ar
y
to
pe
rfo
rm
a
uto
ma
tic
de
ns
ity
is
tha
t th
e
driv
e
au
tom
atic
ally
id
en
tify
the
d
en
sity
o
f a
in
se
rte
d
in
it if
the
first
op
era
tion
is
a
read
o
f se
cto
r 1
ne
ce
ss
ar
y
if th
e
driv
e
is to
b
oot
eith
er
a
d
ou
ble
o
r s
ing
le d
isk
ette
).
sele
ctio
n
dis
ke
tte
(this
is
d
en
sity
Th
e
m1m
mu
m
se
t o
f d
isk
d
rive
fu
nc
tion
s to
s
up
po
rt M
YD
OS
4
(or
A
TA
RI
DO
S
2 fo
r th
at
ma
tter
) are
:
De
vic
e
Un
it C
om
ma
nd
D
irec
tion
B
yte
C
t. A
ux
. B
yte
s
Fu
nc
tion
$
31
Driv
e#
$
21
Fro
m D
rive
128
/2
56
1
to
72
0
FO
RM
AT
D
ISK
$
31
Driv
e#
$
50
T
o D
riv
e
128/
25
6
1 to
72
0
WR
ITE
(no
v
fy)
$3
1 D
rive
#
$5
2
Fro
m D
riv
e 128
/2
56
1
to
72
0
RE
AD
$
31
Driv
e#
$
53
F
rom
D
rive
4
1 to
72
0
RE
AD
S
TA
TU
S
$3
1 D
riv
e#
$
57
To
D
rive
128
/2
56
1
to
720
W
RIT
E(v
er
ify)
Th
e
by
te co
un
t is
alw
ay
s 128
for
a
sma
ll s
ec
tor
d
riv
e,
an
d
is 12
8
for
the
firs
t th
re
e
se
cto
rs
(1,
2, a
nd
3
) o
f a
la
rge
se
cto
r d
rive
. A
ll o
the
r
se
cto
rs
o
n
a
lar
ge
s
ec
tor
driv
e
are
2
56
b
yte
s
lon
g.
Sta
nd
ar
d
do
ub
le
de
nsity
d
isk
ette
s
ha
ve
th
e
lar
ge
or
25
6-
by
te
se
cto
rs
a
nd
a
ll oth
ers
us
e
the
1
28-
by
te
se
cto
r s
ize
.
Th
e
FO
RM
AT
fu
nc
tion
is
ne
ve
r
ca
lled
w
ith
a
se
cto
r n
um
be
r
no
t in
th
e
ra
ng
e
of
4 to
72
0.
It e
xp
ec
ts 128
by
tes
fr
om
a
s
ma
ll se
cto
r d
rive
a
nd
2
56
b
yte
s fro
m
a
lar
ge
se
cto
r (o
r d
ou
ble
d
en
sity
) d
rive
.
pa
ge
2
7
Rev
isio
n
4.3a
Th
e
first b
yte
re
tur
ne
d
by
th
e
RE
AD
S
TA
TU
S
co
mm
an
d
is e
xp
ec
ted
to
in
dic
ate
th
e se
cto
r s
ize
-
-if
bit
5 is
a
1 (b
it 7
is
the
sig
n
bit)
the
n
the
s
ec
tor
s a
re
la
rg
e (2
56
b
yte
s), o
the
rw
ise
, th
ey
a
re
sm
all (12
8
by
tes
).
Th
e
au
xilia
ry
by
tes
a
re tre
ate
d
as
an
a
dd
re
ss
to
a
se
cto
r o
n
the
d
isk
ette
, a
nd
r
an
ge
fr
om
1
to
72
0
(wh
en
in
D
OS
2
com
pa
tible
m
od
el
or
fr
om
1
to 6
5,5
35 (w
he
n a
cc
essin
g
lar
ge
c
ap
ac
ity
dis
k
driv
es
).
Th
e a
dd
ition
al
fun
ctio
ns
us
ed
to
c
on
figu
re
d
isk
driv
es
d
yn
am
ica
lly
ar
e:
De
vic
e
$3
1 $
31
Un
it D
rive
#
Driv
e#
Dir
ec
tion
C
om
ma
nd
$
4E
$
4F
F
rom
D
riv
e
To
D
riv
e
By
te C
t. A
ux
. B
yte
s
Fu
nc
tion
12
1 to
7
20
R
EA
D
CF
G.
12
1 to
720
W
RIT
E C
FG
.
Th
es
e
co
mm
an
ds
a
re
u
se
d
to
co
nfig
ur
e
the
d
rive
s id
en
tified
a
s
co
nfig
ur
ab
le
wh
en
th
e c
om
pu
ter
is
bo
ote
d:
if th
er
e is
a
po
ssibility
th
at
a
driv
e
do
es
n
ot
sup
po
rt th
es
e
fun
ctio
ns
, it
sh
ou
ld
be
d
efin
ed
a
s n
ot
co
nfig
ur
ab
le
(suc
h
as
A
tari
an
d
Ind
us
d
riv
es
). T
he
se c
om
ma
nd
s
als
o
su
pp
or
t th
e
'P'
co
mm
an
d,
pe
rmittin
g
rec
on
figu
ratio
n
of
a
dis
k
driv
e
on
d
em
an
d:
to
for
ma
t a
d
isk
ette
, fo
r
ex
am
ple
. (T
o
for
ma
t a
d
isk
o
n
an
In
du
s d
riv
e, is
su
e th
e
'P'
co
mm
an
d,
ma
nu
ally
c
ha
ng
e th
e
de
ns
ity o
n
the
d
riv
e, th
en
iss
ue
the
'I'
co
mm
an
d).
Th
e
ind
ivid
ual
by
tes
tra
nsfe
rr
ed
b
y
the
se
c
om
ma
nd
s
ar
e
de
fine
d
as
fo
llow
s:
by
te O
: T
ra
ck
s p
er
side
(4
0 fo
r a
s
tan
da
rd
dis
k d
rive
) b
yte
1:
Dis
k
Driv
e
Ste
p
Ra
te (a
s
de
fine
d
by
W
es
ter
n
Dig
ital)
by
te
2:
Se
cto
rs
/T
ra
ck
-
-h
igh
by
te
(us
ua
lly
0)
by
te 3
: S
ec
tor
s/
Tr
ac
k -
-lo
w
by
te(18
for
sta
nd
ar
d
dis
ke
ttes
) b
yte
4:
Sid
e C
od
e
(O:
sing
le
side
d,
l=d
ou
ble
sid
ed
) b
yte
5: D
isk
T
yp
e
Co
de
--
by
te
by
te
by
te
by
tes
bit
2: O
=sin
gle
d
en
sity
, !=
do
ub
le d
en
sity
b
it 1:
0:
5
1/4
inc
h
dis
ke
tte,
1:8
in
ch
d
isk
ette
d
rive
6
: H
igh
b
yte
of B
yte
s/
Se
cto
r (0
fo
r A
TA
RI
810
c
om
pa
tible
) 7:
Lo
w
by
te o
f B
yte
s/S
ec
tor
(128
fo
r A
TA
RI
810
) 8
: T
ra
ns
latio
n
co
ntro
l b
it 7:
1:4
0
trk.
dis
k
I/O
on
an
80
trk
. d
riv
e
bit
6: A
lwa
ys
1
(to
ind
ica
te
driv
e
pr
es
en
t)
bit
1: }:
Ha
nd
le
sec
tors
1, 2,
an
d
3 a
s fu
ll size
se
cto
rs b
it O
: }:
Se
cto
r;;
nu
mb
er
0-
17
(for
ex
am
ple
) n
ot
1-18
9
-1
1 a
re
no
t use
d
by
MY
DO
S
(se
e
the
driv
e
do
cu
me
nta
tion
a
s to
h
ow
th
ey
a
re
to
b
e
se
t -
-u
sua
lly
zero
es
)
MY
DO
S
4 (u
nlik
e
ea
rlie
r
ve
rsion
s o
f M
YD
OS
) a
lwa
ys
is
su
es
a
r
ea
d
co
nfig
ura
tion
c
om
ma
nd
b
efo
re
wr
iting
th
e
co
nfig
ur
atio
n
to
the
d
rive
a
nd
th
e
co
nte
nts
o
f b
yte
s
9-
11 a
re
writte
n
ex
ac
tly
as
the
y
we
re
p
re
vio
us
ly
re
ad
(so
th
ey
w
ill b
e u
nc
ha
ng
ed
).
An
ad
ditio
na
l c
ha
ng
e
in
the
u
sa
ge
o
f th
is
co
mm
an
d
occ
ur
s
wh
en
a
h
igh
c
ap
ac
ity
driv
e
(ha
rd
d
isk
) is
co
nfig
ur
ed
. T
he
c
on
figu
ratio
n
da
ta
for
suc
h
a
driv
e
is v
ery
c
om
ple
x
an
d
is
usu
ally
b
uilt
into
th
e
driv
e
co
ntr
olle
r o
r w
ritte
n
to
a
"ma
gic
" lo
ca
tion
o
n
the
d
isk
.
pa
ge
28 R
ev
isio
n
4.3a
To
s
up
po
rt
pa
rtition
ing
of
ve
ry
la
rge
driv
es
(lar
ge
r
tha
n
16 M
eg
ab
yte
s)
MY
DO
S
iss
ue
s a
w
rite
co
nfig
ura
tion
c
om
ma
nd
w
ith th
e
nu
mb
er
of
se
cto
rs p
er
tra
ck
s
et
to
nu
mb
er
o
f se
cto
rs o
n
the
d
isk
(as
d
efin
ed
in
th
e
'O'
co
mm
an
d)
an
d
the
n
um
be
r o
f tra
ck
s s
et to
1.
All
hig
h
ca
pa
city
d
isk
s a
re
la
rge
se
cto
r d
riv
es
(u
sin
g 2
56
by
te
sec
tor
s).
XI.
RAMD
IS
K
INT
ER
FA
CE
Th
e
driv
er
bu
ilt in
to
MY
DO
S
4 is
inte
nd
ed
to
e
limin
ate
m
ost
of
the
n
ee
d
for
a
"driv
er
" to
u
se
co
mm
on
R
AM
dis
ks
. T
he
r
eq
uir
ed
c
ha
rac
teristic
s o
f th
e
ha
rd
wa
re
ca
n
be
m
ost
ea
sily
de
sc
rib
ed
b
y
ex
pla
inin
g
wh
at
is d
on
e
to
ac
ce
ss
a
"se
cto
r" o
f in
for
ma
tion
in
th
e e
xte
nd
ed
R
AM
.
(1)
the
sec
tor
nu
mb
er
is
div
ide
d
by
12
8,
an
d
the
r
em
ain
de
r
is
the
n
mu
ltiplie
d
by
12
8
an
d
ad
de
d
to 16
38
4 to
g
et
the
sta
rting
a
dd
re
ss
of
the
s
ec
tor
in
me
mo
ry
(it
will
be
be
twe
en
$40
00
an
d
$7
FO
O).
(2)
the
q
uo
tien
t is
use
d
to
ind
ex
into
a
p
ag
e
tab
le
with
o
ne
e
ntr
y fo
r e
ac
h
16K
tha
t ca
n
be
m
ap
pe
d
into
th
e
me
mo
ry
a
rea
from
$
40
00
to
$
7F
FF
.
(3)
the
v
alu
e
from
th
e
pa
ge
ta
ble
is
"A
ND
"ed
w
ith
the
c
on
ten
ts o
f th
e
ma
pp
ing
re
giste
r a
nd
r
ew
ritten
to
th
e
ma
pp
ing
r
eg
iste
r.
(4)
the
d
ata
is
m
ov
ed
to
(from
) th
e
ar
ea
a
dd
re
ss
ed
a
bo
ve
fro
m(to
) th
e
se
cto
r
bu
ffer
s
at
the
h
igh
e
nd
o
f MY
DO
S
(5)
the
m
ap
pin
g
re
gis
ter
is r
es
tor
ed
to
its
no
n-
ma
pp
ing
sta
te
by
"O
R"in
g
the
re
store
v
alu
e
with
th
e
ma
pp
ing
r
eg
iste
r
an
d
re
wr
iting
th
e
re
su
lt to
th
e
ma
pp
ing
r
eg
iste
r.
No
te
tha
t th
is
de
sig
n
for
ce
s
the
R
AM
dis
k
to
be
s
ing
le
de
ns
ity
an
d
no
la
rge
r th
an
4
Me
ga
by
tes
(2
56
p
ag
es o
f 16
38
4 b
yte
s e
ac
h).
As
y
ou
c
an
se
e,
th
e
pa
ram
ete
rs a
re
the
m
ap
pin
g
re
gis
ter
a
dd
re
ss
($
CF
FF
fo
r
Ax
ion
b
oa
rd
s
an
d
$D
30
1 fo
r
the
A
tar
i 13
0X
El,
the
v
alu
e
"OR
"ed
in
to
the
r
eg
iste
r
to
rese
t th
e
sy
ste
m
ba
ck
to
n
or
ma
l (u
sua
lly
$FF
fo
r th
e
Ax
ion
a
nd
$0
0
for
the
A
tari
130
XE
), a
nd
th
e
ac
tua
l m
ap
v
alu
es
. T
he
se
va
lue
s
are
d
ete
rm
ine
d
by
first
ide
ntify
ing
th
e
bits
in
the
m
ap
pin
g
reg
ister
to
be
le
ft u
nc
ha
ng
ed
a
nd
se
tting
th
em
to
"
1"
in
e
ac
h
of
the
re
giste
r v
alu
es
.
Se
co
nd
, the
re
ma
inin
g
bits
are
fille
d
in w
ith a
ll the
le
ga
l co
mb
ina
tion
s of
ma
pp
ing
b
its.
Th
e
va
lue
s fo
r th
e N
ew
ell
Ind
ustrie
s 2
56
K u
pg
rad
e
(wh
ich
u
ses
the
13
0X
E
ma
pp
ing
, m
ore
o
r le
ss) a
re
giv
en
h
er
e
as
an
ex
am
ple
-
futu
re
ve
rsion
s o
f th
is b
oa
rd
an
d
oth
er
me
mo
ry
ex
pa
nsio
n
pr
od
uc
ts
are
n
ot
ne
ce
ssarily
g
oin
g
to
use
the
sa
me
d
es
ign
.
Bits
: 7
6 5
4 3
2 0
pa
ge
2
9
Re
visio
n
4.3a
x x
x x
x F
irs
t, set
bits
7, 1
&
0 in
a
ll th
e m
ap
pin
g
va
lue
s
1 0
0 0
0 0
1 1
Th
ese
are
the
12
(of 3
2)
1 0
0 0
0 1
1 1
1 0
0 0
1 0
1 1
1 0
0 0
1 1
1 1
1 1
0 0
0 0
1 1
1 1
0 0
0 1
1 1
1 1
0 0
1 0
1 1
1 1
0 0
1 1
1 1
1 1
1 0
0 0
1 1
1 1
1 0
0 1
1 1
1 1
1 0
1 0
1 1
1 1
1 0
1 1
1 1
La
stly
, s
inc
e
the
ma
pp
ing
r
eg
iste
r
at
$D
30
1 c
an
b
e
rea
d
as
w
ell
as
w
ritte
n,
it c
an
b
e
left
ex
ac
tly
as
it
wa
s b
efo
re
we
u
se
d
it b
y
"OR
"ing
th
e
initia
l v
alu
e w
ith
ze
ro
(le
av
ing
it
un
ch
an
ge
d).
Th
e
se
qu
en
ce
is
th
en
: B3
, B7
, BB
, BF
, C
3,
C7
, CB
, CF
, E
3, E
7, E
B,
EF
, 0.
XII.
INIT
IAL
INS
TA
LL
AT
ION
IN
ST
RU
CT
ION
S
Th
e
follo
win
g
ch
ec
klis
t is
a
p
roc
ed
ur
e
to
br
ing
u
p
MY
DO
S
4 o
n
a
ne
w
ha
rd
wa
re
co
nfig
ura
tion
. It
sh
ou
ld
be
d
on
e
with
a
n
un
mo
difie
d
co
py
o
f th
e M
YD
OS
4
.3
dis
trib
utio
n
dis
k
an
d
care
sh
ou
ld
be
ta
ke
n
to
pe
rform
th
e
ste
ps
in
ex
ac
tly
the
o
rde
r s
pe
cifie
d.
HO
W T
O
GE
T
FR
OM
TH
E
DR
IVE
WA
Y
TO
T
HE
F
RE
EW
AY
:
1. B
efo
re
tur
nin
g
on
y
ou
r c
om
pu
ter
an
d
dis
k
driv
e,
ma
ke
s
ur
e
tha
t y
ou
do
no
t ha
ve
a
ca
rtridg
e in
sta
lled
in
th
e
co
mp
ute
r.
2.
Tu
rn
on
th
e
dis
k d
rive
, a
nd
wh
en
it stop
s s
pin
nin
g,
ins
er
t th
e
MY
DO
S
ma
ste
r
dis
ke
tte.
Clo
se
the
doo
r if
it ha
s o
ne
.
3.
Tu
rn
on
th
e c
om
pu
ter
: a
fter
sev
era
l se
co
nd
s, th
e M
YD
OS
4 m
en
u
sh
ou
ld
ap
pe
ar
o
n
the
sc
ree
n.
A
pr
om
pt
'Se
lec
t Ite
m
(RE
TU
RN
fo
r m
en
u):'
will
be
disp
lay
ed
.
4.
If y
ou
h
av
e
a
sta
nd
ar
d
2-
driv
e
sy
ste
m
with
s
ing
le
sid
ed
4
0
trac
k
driv
es
an
d e
ithe
r n
o R
AM
dis
k o
r the
sta
nd
ar
d
Ata
ri 130
XE
m
em
or
y
co
nfig
ura
tion
c
on
tinu
e w
ith s
tep
'6
'.
5.
Co
nfig
ure
ea
ch
of
yo
ur
dis
k
driv
es
b
y e
nte
rin
g
the
'O'
co
mm
an
d
follo
wed
b
y
the
d
rive
n
um
be
r,
an
d
an
sw
er
ing
th
e
qu
es
tion
s
the
p
rog
ram
a
sk
s
yo
u.*
6.
If y
ou
n
ee
d
to
ru
n
a
pro
gra
m
tha
t r
eq
uir
es
m
or
e
tha
n
3 d
isk
file
s a
ctiv
e
at
a
time
o
r y
ou
o
the
rw
ise
w
an
t a
lter
o
ne
o
f th
e
de
fau
lt p
ara
me
ter
s,
pr
es
s
the
'O
' k
ey
fo
llow
ed
b
y
the
R
ET
UR
N
ke
y a
nd
a
ns
we
r
the
s
yste
m c
on
figu
ratio
n
qu
es
tion
s.
Th
is
is a
lso
pa
ge
30
R
ev
isio
n
4.3a
NO
TE
S:
wh
er
e
the
R
AM
dis
k
co
nfig
ura
tion
n
ee
ds
to
b
e
en
ter
ed
if
it is
n
ot
a
sta
nd
ar
d
130X
E
RA
Md
isk
o
r n
o
RA
Md
isk
e
xis
ts
in
yo
ur
sy
ste
m.
**
**
7. N
ow
, in
se
rt
a
bla
nk
d
isk
ette
in
the
dis
k
dr
ive
a
nd
fo
rma
t it
with
th
e
'I' c
om
ma
nd
(re
mo
ve
th
e
write
p
rote
ct ta
b
if th
e
dis
ke
tte
is
wr
ite
pro
tec
ted
-
-b
ut
first a
sk
yo
ur
se
lf w
hy
y
ou
p
ut
it th
ere
in
th
e
first p
lace
!). If
an
e
rr
or
m
es
sag
e
is d
isp
lay
ed
, in
se
rt
an
oth
er
d
isk
ette
, th
e
firs
t m
ay
b
e
usa
ble
bu
t it
is
no
t a
g
ood
c
ho
ice
fo
r
yo
ur
sy
ste
m
dis
k
or
sy
ste
m
dis
k
ba
ck
up
.
8.
Wr
ite
the
s
ys
tem
file
s D
OS
.SY
S
an
d
DU
P.S
YS
to
th
e
ne
wly
fo
rm
atte
d
dis
ke
tte w
ith
the
'H
' c
om
ma
nd
a
nd
s
kip
to
ste
p
'10'
if y
ou
d
o
no
t h
av
e
an
A
TA
RI
130X
E
co
mp
ute
r o
r
som
e
oth
er
R
AM
dis
k
usa
ble
w
ith
the
MY
DO
S
RA
Md
isk
d
riv
er
.
9.
If y
ou
h
av
e
an
A
TA
RI
130X
E
com
pu
ter
o
r h
av
e
an
oth
er
kin
d
of
RA
Md
isk
a
nd
w
ish
to
u
se th
e M
YD
OS
R
AM
dis
k
driv
er
, c
op
y
RA
MB
OO
T3
.AU
T
on
th
e
ma
ster
dis
ke
tte
to
AU
TO
RU
N.S
YS
o
n
the
n
ew
d
isk
ette
(u
se th
e
'C'
co
mm
an
d,
an
d
if y
ou
h
av
e
on
ly
on
e
driv
e,
en
ter
the
c
om
ma
nd
lin
e
'RA
MB
OO
T.A
UT
,AU
TO
RU
N.S
YS
/X
' w
he
n M
YD
OS
as
ks
for
the
file
na
me
s).U
10.
Th
is
is
no
w
yo
ur
prim
ary
s
yste
m
ba
ck
up
d
isk
: p
lac
e
a
write
p
rote
ct
tab
o
n
it, la
be
l it
an
d
us
e
the
'J
' c
om
ma
nd
to
m
ak
e
as
ma
ny
w
ork
ing
b
oot d
isk
s a
s y
ou
ne
ed
fro
m
it.
Th
e
RA
MB
OO
T3
pro
gra
m
will
co
py
th
e
files
in
a
dir
ec
tor
y
ca
lled
R
AM
DIS
K
on
y
ou
r b
oot
dis
k
to
the
R
AM
dis
k
if s
uc
h
a
dir
ec
tor
y
ex
ists
. T
o
tak
e
ad
va
nta
ge
o
f th
is
featu
re
, u
se
th
e
'Q'
co
mm
an
d
to
cre
ate
th
e d
irec
tory
a
nd
co
py
th
e file
s y
ou
w
an
t o
n
the
.RA
Md
isk
to
it.
* -
-T
he
s
tep
r
ate
is
a
c
ry
ptic
c
od
e
tha
t ra
ng
es
fr
om
0
(fas
t) to
3
(ve
ry
slow
). M
ost
driv
es
will
wo
rk
w
ith
0 o
r 1
bu
t y
ou
m
ay
n
ee
d
to
ex
pe
rime
nt
with
it
to
find
th
e b
es
t sp
eed
for
yo
ur
dr
ive
s
(an
d
po
we
r s
up
plie
s).
**
--
Th
e
sou
rce
file
fo
r th
e R
AM
d
isk
boo
t is a
lso
inc
lud
ed
, if
yo
u
fee
l th
e u
rg
e,
mo
dify
it
pe
rfor
m o
the
r
tas
ks
--
RA
MB
OO
T2
c
on
figu
re
s
the
R
AM
dis
k, fo
rma
ts
it, m
ov
es
it
to
driv
e
8,
en
ab
les
ME
M.S
AV
an
d
co
pie
s D
UP
.SY
S
to
it, R
AM
BO
OT
3 c
on
figu
re
s it,
form
ats
it, en
ab
les
M
EM
.SA
V,
co
pie
s
DU
P.S
YS
to
it
an
d
also
c
op
ies
a
ll th
e
files
in
D
l:RA
MD
ISK
: to
it.
RA
MB
OO
T3
, th
e
on
e
dis
trib
ute
d
as
AU
TO
RU
N.S
YS
m
us
t a
lso
b
e
the
la
st A
UT
OR
UN
file in
AU
TO
RU
N.S
YS
s
inc
e it u
se
s a
ll 3 d
isk
b
uffe
rs
in
a
sta
nd
ard
M
YD
OS
. A
n
imp
rov
ed
v
er
sion
w
itho
ut
this
lim
itatio
n
will
be
r
ele
ase
w
ith
the
n
ex
t v
er
sio
n.
If y
ou
re
co
mp
ile
RA
MB
OO
T2
a
nd
u
se
it,
rem
em
be
r
tha
t w
he
n
yo
u
string
to
ga
the
r
sev
era
l A
UT
OR
UN
file
s, o
nly
th
e
last w
ill ha
ve
its
R
UN
ad
dr
es
s in
vo
ke
d.
**
**
--
NE
WE
LL
IND
US
TR
IES
8
00
XL
U
PG
RA
DE
--
pa
ge
31
Re
visio
n
4.3a
this
R
AM
dis
k
can
u
se
p
ag
e s
eq
ue
nc
e
0 o
r p
ag
e
se
qu
en
ce
1.
Th
e
E3
/E
7 /E
B/
EF
pa
ge
s
ca
n
be
re
se
rv
ed
fo
r B
AS
IC/
XE
in
e
xte
nd
ed
m
od
e
by
se
tting
th
e
RA
Md
isk
s
ize
to
128
K
an
d
the
s
eq
ue
nc
e
to
1. E
nte
r S
ize
=128
(or
19
2
if y
ou
w
ill n
ot
be
u
sin
g
BA
SIC
/X
E
ofte
n),
Co
ntro
l a
dd
re
ss
=D3
01,
an
d
Pa
ge
s
eq
ue
nc
e=
l. In
th
e
se
co
nd
c
ase
th
is
will
us
e
the
a
re
a
also
u
sed
b
y
BA
SIC
/X
E,
bu
t it
will a
cc
es
s
it o
nly
a
fter
the
fir
st
128
K
ar
e
use
d
up
. B
y
settin
g
the
s
ize
to
12
8K
, B
AS
IC/
XE
a
nd
th
e
RA
Md
isk
a
re
fully
s
ep
ara
te a
nd
c
an
no
t in
ter
fer
e
with
e
ac
h
oth
er
. U
U
--
AX
LO
N R
AM
PO
WE
R
128 fo
r th
e A
tar
i 80
0
co
mp
ute
r
--
MY
DO
S
4.0
c
om
es
c
on
figu
re
d
for
th
e
Ata
ri
130
XE
-
-if
yo
u
are
in
sta
lling
it
on
a
n
80
0
with
a
n
Ax
ion
R
AM
PO
WE
R
bo
ar
d,
yo
u
mu
st
disa
ble
th
e
128K
m
od
e
on
th
e
RA
MP
OW
ER
b
oa
rd
u
ntil
yo
u
ha
ve
c
on
figu
red
th
e
MY
DO
S
RA
Md
isk
c
od
e
by
e
nte
ring
S
ize
=1
12,
Co
ntro
l a
dd
re
ss
=C
FF
F
an
d
Pa
ge
se
qu
en
ce
=5
. T
he
n
write
the
D
OS
b
ac
k
to
a
ne
w
dis
ke
tte,
co
py
A
UT
OR
UN
.SY
S
to
it, sw
itch
th
e
RA
MP
OW
ER
b
oa
rd
b
ac
k
to
128K
a
nd
b
oot
up
th
e
ne
w
dis
ke
tte.
pa
ge
3
2
Re
vis
ion
4
.3a
XII.
ER
RO
R
CO
DE
S
AND
T
HE
IR
SO
UR
CE
S
3 L
as
t b
yte
of
file rea
d,
ne
xt
read
w
ill r
etu
rn
E
OF
(M
YD
OS
) 12
8
Br
ea
k
Ab
or
t (O
S R
OM
s)
129
IO
CB
alre
ad
y
op
en
(O
S
RO
Ms
) 130
No
s
uc
h
de
vic
e
de
fine
d
in
the
sy
ste
m
(OS
R
OM
s)
131
Wr
ite-
on
ly
IOC
B,
ca
nn
ot
rea
d
(OS
R
OM
s)
132
Inv
alid
c
om
ma
nd
(O
S
RO
Ms
) 13
3 D
ev
ice
o
r F
ile n
ot
op
en
(O
S
RO
Ms
) 13
4
Inv
alid
IO
CB
re
fer
en
ce
(O
S
RO
Ms
) 13
5
Re
ad
-o
nly
IO
CB
, ca
nn
ot
wr
ite (O
S
RO
Ms
) 13
6
Atte
mp
t to re
ad
p
ast
en
d o
f file
(MY
DO
S)
137
T
ru
nc
ate
d
rec
ord
(O
S
RO
Ms
) 138
D
ev
ice
T
ime
ou
t (O
S
RO
Ms
) 13
9
De
vic
e N
AK
(seria
l b
us
fa
ilur
e,
OS
R
OM
s)
141
Cu
rso
r ou
t of
ra
ng
e
for
gr
ap
hic
s
mo
de
(O
S R
OM
s)
142
D
ata
fra
me
o
ve
rr
un
(s
eria
l b
us
failu
re
, O
S
RO
Ms
) 14
3
Da
ta
fra
me
c
he
ck
su
m
er
ror
(se
rial
bu
s fa
ilur
e, O
S
RO
Ms
) 14
4
De
vic
e 1/
0 e
rr
or
(in
pe
riph
era
l h
ar
dw
ar
e,
OS
R
OM
s)
146
F
un
ctio
n n
ot p
rov
ide
d
by
ha
nd
ler
(O
S
RO
Ms
) 14
7
Ins
uffic
ien
t RA
M
for
gr
ap
hic
s m
od
e se
lec
ted
(O
S
RO
Ms
) 16
0
Inv
alid
U
nit/
Dr
ive
Nu
mb
er
, z
er
o
or
gr
ea
ter
th
an
9
(bo
th
MY
DO
S
an
d O
S
RO
Ms
) 16
1 N
o
se
cto
r b
uffe
r a
va
ilab
le,
too m
an
y o
pe
n file
s (M
YD
OS
) 16
2
Dis
k fu
ll, c
an
no
t a
lloc
ate
sp
ac
e fo
r o
utp
ut file
(MY
DO
S)
163
W
rite
p
ro
tec
ted
o
r
sy
ste
m
er
ror
-
if
the
d
isk
is
n
ot
wr
ite
pr
otec
ted
, it sh
ou
ld
be
c
op
ied
to
a
no
the
r
dis
k
imm
ed
iate
ly
--
the
file
sy
ste
m is
c
orru
pte
d
(MY
DO
S)
164
F
ile
nu
mb
er
in
lin
k
do
es
n
ot
ma
tch
th
e
file's
d
ire
cto
ry
lo
ca
tion
(M
YD
OS
) 16
5
Inv
alid
file
n
am
e
(MY
DO
S)
166
B
yte
n
ot w
ithin
file,
inv
alid
P
OIN
T
re
qu
es
t (MY
DO
S)
167
F
ile
loc
ke
d, c
an
no
t b
e a
lter
ed
(M
YD
OS
) 168
In
va
lid
IOC
B
(MY
DO
S
an
d
OS
R
OM
s)
169
D
ire
cto
ry
fu
ll, c
an
no
t c
re
ate
a
6
5-
th
en
try
in
a
d
ire
cto
ry
e
ntr
ies
m
ay
b
e u
se
d
for
'los
t' a
s w
ell a
s
rea
l files
(M
YD
OS
) 17
0
File
no
t in d
ire
cto
ry
, ca
nn
ot
be
op
en
ed
for in
pu
t (MY
DO
S)
171
IOC
B
no
t op
en
(M
YD
OS
an
d O
S R
OM
s)
172
*
File
or
d
ire
cto
ry
o
f
sam
e
na
me
a
lrea
dy
ex
ists
in
pa
re
nt
dir
ec
tor
y,
ca
nn
ot c
re
ate
(M
YD
OS
) 17
3
Ba
d d
isk
ette
o
r d
riv
e,
ca
nn
ot fo
rm
at
dis
ke
tte
(MY
DO
S)
174
*
Dir
ec
tor
y
no
t in
p
are
nt d
ire
cto
ry
(M
YD
OS
) 17
5*
D
ire
cto
ry
n
ot e
mp
ty,
ca
nn
ot
de
lete
(M
YD
OS
) 18
0*
Inv
alid
file
s
tru
ctu
re
fo
r lo
ad
ing
m
em
or
y
(MY
DO
S)
181*
In
va
lid
ad
dr
es
s r
an
ge
for
loa
din
g m
em
or
y,
EN
D<B
EG
IN
(MY
DO
S)
* -
-N
ew
e
rro
r c
od
es
, n
ot
pr
es
en
t or
diffe
re
nt in
Ata
ri D
OS
2
.
Mo
st e
rro
r
co
de
s
ar
e
ide
ntica
l to
th
ose
r
etu
rn
ed
fro
m A
TA
RI
DO
S 2
, th
e
diffe
re
nc
es
r
es
ult
from
th
e
ex
pa
nd
ed
c
ap
ab
ilities
of
MY
DO
S
4.
Sp
ec
ifica
lly,
Er
ro
r
164
, ind
ica
ting
a
file
n
um
be
r
mis
ma
tch
, o
nly
oc
cu
rs
if
the
file
is w
ritte
n
in
DO
S
2 o
r
AT
AR
I D
OS
I
form
at.
Er
ro
rs
18
0 a
nd
18
1 c
an
o
nly
o
cc
ur
w
he
n X
IO
39
is
in
vo
ke
d
to lo
ad
a
file
, th
e A
TA
RI
DO
S
2 e
qu
iva
len
t fun
ctio
n
re
tur
ne
d
a
cod
e in
th
e
X-
re
gis
ter
. E
rr
or
s
172
a
nd
pa
ge
33
R
ev
ision
4
.3a
175
ap
ply
to
c
rea
ting
a
nd
d
ele
ting
d
irec
torie
s a
nd
h
av
e n
o
AT
AR
I D
OS
2
eq
uiv
ale
nt.
An
d
Er
ror
174
a
pp
lies
to
ac
ce
ss
ing
file
s in
s
ub
dire
cto
ries
, so
it
also
h
as
n
o
AT
AR
I D
OS
2
eq
uiv
ale
nt.
Er
ror
co
de
17
3
se
rv
es
th
e
sam
e
fun
ctio
n
as
it
did
in
A
TA
RI
DO
S
2,
bu
t is
r
etu
rn
ed
m
ore
o
ften
(to
id
en
tify
ba
d
dis
ke
ttes
m
ore
relia
bly
),
pa
ge
3
4
Re
visio
n
4.3a
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