Equipment List
This identifies equipment and peripheral options which are installed
and/or active. It is returned from INT 11H (in AX) and can be found in
the BIOS Data Area at 0040:0010.
EquipmentListRec
1 1 1 1 1 1
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ºprt³ ³j³ aux ³ ºdrv³vid³ram³n³dº
ÓÄÁÄÁÒÁÒÁÄÁÄÁÄÁÒÐÄÁÄÁÄÁÄÁÄÁÄÁÒÁÒ½ bits mask
È˼ º º ÈÍËͼ º È˼ È˼ È˼ º ÈÍ> 0: 0001H disk drives are present
º º º º º º º º ÈÍÍÍ> 1: 0002H numeric coprocessor present
º º º º º º º ÈÍÍÍÍÍÍ> 2-3: 000eH motherboard RAM
º º º º º º ÈÍÍÍÍÍÍÍÍÍÍ> 4-5: 0030H Initial/active video mode
º º º º º ÈÍÍÍÍÍÍÍÍÍÍÍÍÍÍ> 6-7: 00c0H total diskettes drives-1
º º º º ÈÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ> 8: 0100H DMA present
º º º ÈÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ> 9-11: 0e00H RS232 serial ports
º º ÈÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ> 12: 1000H game adapter present
º ÈÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ> 13: 2000H serial printer (PCjr)
ÈÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ>14-15: c000H printers installed
bit 0 When this is 0, the computer has no diskette drives.
bit 1 1 means that a numeric coprocessor is present. This is not
always reliable on older BIOSes.
bits 2-3 motherboard memory: 01=16K; 10=32K; 11=64K+ (usually 00 on
most modern PCs, so has no meaning)
On PS/2s, bit 2 is 1 when a mouse is detected by the POST
bits 4-5 Currently-active video adaptor. It is one of:
00=(reserved) 10=80-clm color
01=40-clm color 11=TTL Monochrome
bits 6-7 number of detected diskette drives -1:
00=1; 01=2; 10=3; 11=4
bit 8 1 = DMA hardware is present (not reliable)
bits 9-11 detected RS-232 serial ports detected:
000=0; 001=1...100=4...111=7
bit 12 1=game adaptor (joystick) was detected by POST.
bit 13 (on PCjr only) 1=serial printer attached
bits 14-15 number of parallel printer ports:
00=0; 01=1; 10=2; 11=3
Notes: þ This data word is often used to ascertain the active video
adaptor and the location of video RAM.
If (AX & 30H) == 30H then the Monochrome adapter is active
and video RAM segment is at b000H, otherwise use b800H. See
Video Memory Layouts.
þ In general, the Equipment List word does not impart much useful
information reliably. For instance, even when bits 9-11
indicate 4 serial ports, the computer may provide support for
4 ports, but the hardware to handle only one or two is actually
present.
See Also: BIOS Data Area
INT 11H
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