Register A
other
than
OOH
and
FFH
- Indicates
that
the address in
HL
is
not
within the VRAM area.
The
contents
of
register B
and
register pair
HL
are
not
changed.
Entry Point: WBOOT
+ 33H
SCRNDUMP is the entry point for the subroutine which prints a
hard
copy
of
the
LCD
screen image
on
the printer.
It
is terminated
by
pressing
the
CTRL-
STOP
key.
Return Parameters
F67EH (LSTERR)
OOH
- normal operation
F67EH (LSTERR)
=
FFH
- Terminated
by
CTRL-STOP
5.7.5 BIOS Subroutines related to the Disk operation
In·'M.
Entry Point: WBOOT +
I5H
HOME
is
the entry point for the subroutine which sets the track
to
zero.
Entry Point: WBOOT
+
I8H
SELDSK is the entry point for the subroutine which specifies a disk drive.
Entry parameter
Register C
OOH
Drive A:
Register C OIH Drive
B:
Register C 02H Drive C:
Register C 03H Drive D:
Register C 04H Drive E:
Register C 05H Drive F:
Register C 06H Drive G:
Register C 07H Drive H:
HL
register includes the disk parameter header address.
5-16
~
~
:;,
I
~
,
..
\
~
;\ I
.~
--
I
.~
e ,
~,I
,
~I
~
C:
I
~
~;
I
~
~~
I
.~
~~
L.~
~L~
~\
L~
~\
I ,
~.
L"
.\L.~
.L..,
.L-,
..
L-,
~
~
Return Parameters
Register
HL
=
OOH
Indicates
that
a parameter error has occurred.
Register
HL
is
not
OOH
Normal operation
,*_
..
*.
Entry
Point: WBOOT +
IBH
SETTRK is the entry point for the subroutine which selects the track
to
be read
from
or
written to.
Entry parameter
Register BC
= Track number
The track number varies according
to
the drive as shown below.
It
can be any
number from zero
to
that
shown in the following table:
Drive Default
Track
number Default Device
A:
o
to
I (Max.
2)
Internal
RAM
disk
o
to
6
60K RAM Disk Unit
o
to
13
I20K RAM Disk Unit
B:
o
to
3
ROM I (32K ROM)
C:
ROM
2 (32K ROM)
D:
FDD
I
E:
FDD2
F:
o
to
39
FDD
2
G:
FDD
4
H:
o
to
4 Microcassette drive
If
a value which
is
not
within the above range
is
specified, an error occurs when
a read
or
write
is
performed. These values assume
that
the default settings for
the drive assignments hold. See section 3.8.6 for further details
of
drive as-
signments.
NOTE:
Maximum track number changes
in
accordance with the sign
of
RAM
disk set
by
CONFIG.
'*"*"'
Entry
Point: WBOOT +
IEH
5-17
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