Port 80 Codes - I-Bus IBC 2600 User Manual

PORT 80 CODES

The following codes are presented on Port 80H as the BIOS performs its
reset procedure.
Code Description
Uncompressed Initialization Code Checkpoints:
D0 NMI is disabled. Power-on delay starting. Initialization code
checksum to be verified next.
D1 Initializing DMA controller, performing keyboard controller BAT
test, starting memory refresh and entering 4GB flat mode next.
D3 Starting memory sizing next.
D4 Returning to real mode. Executing any OEM patches and
setting stack next.
D5 Passing control to uncompressed code in shadow RAM at
E000:0000H. Initialization code copied to segment 0 and
control to be transferred to segment 0.
D6 Control in segment 0. Checking if <Ctrl>+<Home> was pressed
and verifying system BIOS checksum, If <Ctrl>+<Home> was
pressed or system BIOS checksum is bad, going to checkpoint
code E0H next. Otherwise, going to checkpoint code D7H.
D7 Main BIOS runtime code to be decompressed and control to be
passed to main BIOS in shadow RAM.
Boot Block Recovery Code Checkpoints:
E0 Onboard floppy controller initialized, if any. Beginning base
512KB memory test next.
E1 Initializing interrupt vector table next.
E2 Initializing DMA and interrupt controllers next.
E6 Enabling floppy drive controller and timer IRQ's. Enabling
internal cache memory.
ED Initializing floppy drive.
EE Looking for floppy diskette in drive A:. Reading first sector of
diskette.
EF Read error occurred while reading floppy drive in drive A:.
F0 Searching for AMIBOOT.ROM file in root directory.
IBC 2600 User's Guide
Appendix 1 - BIOS Messages
A1-7