ErgoPro e-, x- and s- Series PC Specialist's Handbook
Page 60 First Edition, Release 4 - June 1998
A0 Reset cause = Boot request. Enable NMI and parity checking. The address line A20 is gated off.
A1 If any password is installed in CMOS memory then a prompt for the password is displayed and a
password is read. When a correct password is given, control continues at checkpoint A2.
A2 Print a new line and do interrupt 19 (boot system).
A3 Copy option PROM to shadow RAM.
B0 Enter INT 19. Set up floppy parameters to BIOS default.
B1 Select floppy drive A:.
B2 Clear memory locations 0000:7C00 to 0000:7E00.
B3 Check if floppy boot is enabled in CMOS memory.
B4 Try loading a boot sector from floppy drive A:. Boot sector is good if last two bytes = 55 AA.
B5 Try loading a boot sector from floppy drive B:. If boot sector is good (last two bytes = 55 AA) then next
checkpoint is BB.
B6 Send reset command to hard disk controller via normal BIOS interrupt 13, function 00.
B7 Read hard disk parameters via BIOS interrupt 13, function 08. If error (from BIOS interrupt or recorded
in CMOS memory) or no hard disks then try drive A: once every second.
B8 Read boot sector into memory location 0000:7C00.
B9 A retry is performed (five retries total). Reset hard disk controller with BIOS interrupt 13, function 0D.
BA Insure that the last two bytes of the boot sector contain 55, AA. If not then try boot from A: once every
second.
BB Clear screen and jump to location 0000:7C00.
F6 Load video BIOS from floppy.
F7 Load power management BIOS from floppy.
F8 Load system BIOS from floppy.
F9 Start flash programming. Write enable flash.
FA Identify flash.
FB Program flash with zeros.
FC Erase flash.
FD Program flash with new data.
FE Reset flash to read mode and write disable flash.
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