The feature bits are set from Input Status register 0 in response to an output on the specified Feature Control register bits:Obtains configuration information for the active video subsystem.
Call with:
AH = 12H
BL = 10H
Returns:
BH = display type
0 if color display
1 if monochrome display
BL = memory installed on EGA board
00H if 64 KB
01H if 128 KB
02H if 192 KB
03H if 256 KB
CH = feature bits (see Notes)
CL = switch setting (see Notes)
Notes:
The feature bits are set from Input Status register 0 in response to an output on the specified Feature Control register bits:
Feature Feature control Input status bit(s) output bit bit 0 0 5 1 0 6 2 1 5 3 1 6 4—7 not used
The bits in the switch settings byte indicate the state of the EGA's configuration DIP switch (1 = off, 0 = on).
Bit(s) Significance 0 configuration switch 1 1 configuration switch 2 2 configuration switch 3 3 configuration switch 4 4—7 not used