Code |
Meaning |
01 |
Processor test 1; processor status verification |
02 |
Determine type of POST test. Failed if keyboard interface buffer filled with data. |
06 |
Init 8259 PIC and 8237 DMA controller chips. Disable colour and mono video, parity circuits and DMA chips. Reset math coprocessor. Initialise 8253 Timer channel 1. Clear DMA chip and page registers. |
07 |
Processor test #2. Write, read and verify all registers except SS, SP and BP with data patterns 00 and FF. |
09 |
EPROM checksum for 32 Kbytes |
0A |
Initialize video controller 6845 registers as follows: 25 lines x 80 columns, first cursor scan line at 6/11 and last at 7/12, reset display offset to 0. |
15 |
Test 1st 64K of system memory |
16 |
Setup interrupt vector table in 1st 64K |
17 |
Setup video I/O operations |
18 |
Test video memory |
19 |
Test 8259 channel 1 mask bits |
1A |
Test 8259 channel 2 mask bits |
1D |
Setup configuration byte from CMOS |
1E |
Sizing system memory & compare w/CMOS |
1F |
Test found system memory |
20 |
Test stuck 8259's interrupt bits |
21 |
Test stuck NMI (parity/IO chk) bits |
22 |
Test 8259 interrupt functionality |
2A |
Initialise keyboard |
2B |
Initialise floppy controller and drive |
2C |
Initialise COM ports |
2D |
Initialised LPT ports |
2F |
Initialise maths coprocessor |
31 |
Initialise option ROMs |
FF |
Int 19 Boot attempt |
