MITSUBISHI ELECTRIC FC810 User Manual
Page 30
MITSUBISHI ELECTRIC MOTHERBOARD DIVISION
PAGE 30 OF 45
The BIOS also issues Port 80h codes that can be displayed using a suitable diagnostic card. The
codes can be used to determine the failure.
('
02h
Verify Real Mode
03h
Disable Non-Maskable Interrupt (NMI)
04h
Get CPU type
06h
Initialise system hardware
08h
Initialise chipset with initial POST values
09h
Set IN POST flag
0Ah
Initialise CPU registers
0Bh
Enable CPU cache
0Ch
Initialise caches to initial POST values
0Eh
Initialise I/ O component
0Fh
Initialise the local bus IDE
10h
Initialise Power Management
11h
Load alternate registers with initial POST values
12h
Restore CPU control word during warm boot
13h
Initialise PCI Bus Mastering devices
14h
Initialise keyboard controller
16h
BIOS ROM checksum
17h
Initialise cache before memory autosize
18h
8254 timer initialisation
1Ah
8237 DMA controller initialisation
1Ch
Reset Programmable Interrupt Controller
20h
Test DRAM refresh
22h
Test 8742 Keyboard Controller
24h
Set ES segment register to 4 GB
26h
Enable A20 line
28h
Autosize DRAM
29h
Initialise POST Memory Manager
2Ah
Clear 512 KB base RAM
2Ch
RAM failure on address line
2Eh
RAM failure on data bits of low byte of memory bus
2Fh
Enable cache before system BIOS shadow
30h
RAM failure on data bits of high byte of memory bus
32h
Test CPU bus- clock frequency
33h
Initialise Phoenix Dispatch Manager
34h
Test CMOS RAM
35h
Initialise alternate chipset registers.