Code |
Meaning |
01 |
Jump to reset area in ROM BIOS |
02 |
Initialize DMA page register |
03 |
Initialize DMA refresh register |
04 |
Clear all RAM |
05 |
Perform RAM test on 1st 64k |
06 |
Clear 1st 64k |
07 |
Initialize BIOS stack to 0:FC0 |
08 |
Set the equipment flag based on switches |
09 |
Initialize default interrupt vectors |
0A |
Initialize 8255 if it exists and enable parity |
0B |
Initialize 8259 and enable interrupts |
0C |
Setup adapters and peripherals |
0D |
Setup video |
0E |
Initialize video |
0F |
Initialize equipment |
10 |
Initialize memory configuration in RAM (currently = 64K) |
11 |
Setup timer function |
12 |
Initialize timer function |
13 |
Setup time of day function |
14 |
Initialize time of day function |
15 |
Setup and init print screen function |
16 |
Setup and init cassette function |
17 |
Setup and init bootstrap function |
18 |
Setup and init keyboard function |
19 |
Enable speaker |
1A |
Setup timer 0 for the real time clock |
1B |
EnabIe RTC |
1C |
Setup timer 2 for the beeper |
1D |
Size memory: write 55AA/AA55 to 1st/last word in segment |
1E |
Read 1st and last word of segment |
1F |
Compare 1st and last words |
20 |
Report determined memory size to screen |
21 |
Perform checksum on ROM BIOS |
22 |
If cold boot perform complete RAM testing |
23 |
Move system stack to bottom of memory and save pointer at 40:0E |
24 |
Reset parity after RAM sizing |
25 |
Enable timer and keyboard interrupts |
26 |
Setup the serial and parallel ports |
27 |
Setup the game port |
28 |
Setup the floppy disk controller |
29 |
Scan for optional ROM in 2K chunk from C8000 to start of BIOS |
2A |
Boot System |
