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.

1 1 1 1 1 1
 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 
 prt   j  aux    drv vid ram n d 
                                   bits   mask
                                     0: 0001H disk drives are present
                                    1: 0002H numeric coprocessor present
                                  2-3: 000eH motherboard RAM
                                  4-5: 0030H Initial/active video mode
                                  6-7: 00c0H total diskettes drives-1
                                    8: 0100H DMA present
                                 9-11: 0e00H RS232 serial ports
                                   12: 1000H game adapter present
                                   13: 2000H serial printer (PCjr)
                                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:   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

  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

See Also: BIOS Data Area
- -

Equipment List