INT 11h (17) Read Equipment-List
Returns a list of installed equipment on the system.
On entry: No parameters
Returns: AX Equipment code
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Equipment code (AX)
F E D C B A 9 8 7 6 5 4 3 2 1 0
x x . . . . . . . . . . . . . . Number of printers installed
. . x . . . . . . . . . . . . . Internal modem installed
. . . x . . . . . . . . . . . . Game adapter installed? (always 1 on PCJr)
. . . . x x x . . . . . . . . . Number of RS-232 ports
. . . . . . . x . . . . . . . . Reserved
. . . . . . . . x x . . . . . . Number of diskettes - 1 (i.e. 0=1 disk)
. . . . . . . . . . x x . . . . Initial video mode (see below)
. . . . . . . . . . . . x . . . Reserved
. . . . . . . . . . . . . x . . Reserved
. . . . . . . . . . . . . . x . Math coprocessor installed?
. . . . . . . . . . . . . . . x 1=diskettes present; 0=no disks present
Initial video mode
Value Meaning
00 Reserved
01 40 x 25 Color
10 80 x 25 Color
11 80 x 25 Monochrome
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Notes: The value returned in AX is the same as that stored
at memory location 0:0410h, which is initialized
during the power-up tests.
For the IBM PC, XT, and PCjr, bits 2 and 3 used to
list the amount of RAM installed on the system board
in increments of 16K. For example, 00 meant 16K,
while 11 meant 64K.
Bit 0 indicates only whether the system has one or
more diskette drives. Refer to bits 6 and 7 to find
out how many diskettes are actually present. To
determine the number of hard disks installed, use
INT 13h, Service 8.
If the DIP switches for PCs and XTs are not set
correctly reflecting the presence of a math
coprocessor, then bit 1 (math coprocessor present)
may be incorrect. A better test for the math
coprocessor is to test it directly by executing a
math coprocessor instruction and then checking to
see if the instruction was executed.
Seealso:
This page last updated on Fri Nov 30 10:49:50 MSK 2001
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