IBM PC CONVERTIBLE

Turn on power to
adapter at hex
2F8.
Delay 100 ms.
Write/read hex
AA and 55 to
work register at
hex 2FF.
Turn off power to
adapter.
Delay 100 ms.
Yes (Attached)
Yes (serial/
parallel
attached)
Set RS232_BASE
table entry to hex
2F8.
Move
RS23LBASE
table pointer to
next entry.
Set equipment
word for number
of printer and
communications
ports installed.
Figure 1-3 (Part 7 of 7). Printer/Communications Presence Test
1-18 Power-On Self-Test (POST)