Table of Contents
Advertisement
Basic I/O System (BIOS) Functions
Two CP/M-86 utilities use the IOBYTE:
• PIP allows access to the physical devices;
• ST A T allows logical-physical assignments to be made and displayed.
Table 5-3 IOBYTE Field Defintions
CONSOLE field (bits 0, 1)
o -
console is assigned to the console printer (TTY:)
I - console is assigned to the CRT device (CRT:)
2 - batch mode; use the READER as the CONSOLE input, and the LIST
device as the CONSOLE output (BAT:)
3 - user-defined console device (UCI:)
READER field (bits 2, 3)
0- READER is the Teletype device (TTY:)
1 - READER is the high-speed reader device (RDR:)
2 - user-defined reader # 1 (UR 1:)
3 - user-defined reader #2 (UR2:)
PUNCH field (bits 4, 5)
0- PUNCH is the Teletype device (TTY:)
1 - PUNCH is the high speed punch device (PUN:)
2 - user-defined punch # 1 (UP 1:)
3 - user-defined punch #2 (UP2:)
LIST field (bits 6, 7)
0- LIST is the Teletype device (TTY:)
1 - LIST is the CRT device (CRT:)
2 - LIST is the line printer device (LPT:)
3 - user-defined list device (UL1:)
NOTE
The implementation of the IOBYTE is
not fully supported by the NEC BIOS.
IOBYTE has been implemented on the
APC only for assigning the LIST device
to either LPT: or UL1: as follows.
LPT:
=
Parallel centronix interface
UL 1:
=
Serial RS 232C interface
(standard on APC)
5-9
Advertisement
Table of Contents
