INT 15 - Compaq ROM(Read-Only Memory) A memory for program storage which may not be changed by the program as it runs. BIOS(Basic Input/Output System) A set of standardized calls giving low-level access to the hardware. The BIOS is the lowest software layer above the actual hardware and serves to insulate programs (and operating systems) which use it from the details of accessing the hardware directly. 1993/08/03 and newer - ???
AH = E4h
AL = subfunction
00h get advanced system info
Return: CF clear
AH = 00h
CX = 0000h
BX = advanced system info flags (read from [XBDAsee Extended BIOS Data Area:0094h])
bit 4: "mode 2" (dual harddisk controller) enabled
01h,02h unsupported by this ROM(Read-Only Memory) A memory for program storage which may not be changed by the program as it runs. version
Return: CF set, AH = 86h
80h set advanced system info
BX = advanced system info flags
bit 4: enable "mode 2" (dual harddisk controller)
???
Return: ???
Note: On Compaq machines with "COMPAQ" signature at
F000h:FFEAh (see also MEM F000h:FFE0h), MS-DOS/PCIBM PC DOS
IO.SYS/IBMBIO.COM use this function to set bit 4
before calling INT 13h/AH=08h to retrieve the number
of hard disks installed (DL).
90h,A0h,B0h,C0h,D0h,E0h,F0h set ???
Return: CF clear
AH = 00h
CX = 0000h
BX = ???
81h,91h,A1h,B1h,C1h,D1h,E1h,F1h unsupported by 3/8/93&4/8/93 ROMs
Return: CF set, AH = 86h
Notes: functions 80h/90h/etc. are not supported by the 4/8/93 EISA(Enhanced Industry-Standard Architecture) A 32-bit superset of the IBMInternational Busiuness Machines ATIBM PC AT's expansion bus (which is now known as the ISA or Industry-Standard Architecture bus). System ROM(Read-Only Memory) A memory for program storage which may not be changed by the program as it runs.
these functions are not supported by the 7/26/93 LTE Lite 386 ROM(Read-Only Memory) A memory for program storage which may not be changed by the program as it runs.