Tandy 1000 Programmer's Reference Manual page 215

Chmter 6
I
BIOS Services
Equipment
This service returns the "equipment flag" (hardware configura-
tion of the computer system) in the AX register.
Software Interrupts:
11 hex (17 dec)
The "equipment flag" returned in the AX register has the mean-
ings listed below for each bit:
Reset
=
the indicated equipment is not in the system
Set
=
the indicated equipment is in the system
bit 0 diskette installed
bit 1 not used
bit 2,3 always
=
11
bit 4,5 initial video mode
01
=
4 0 ~ 2 5 B W
10
=
80x25BW
number of diskette drives (only if bit 0
=
1)
00
=
1
01
=
2
0
=
dma present
1
=
no dma on system
bit 6,7
bit 8
bit 9, 10, 11 number of RS 232 cards
bit 12
game I/O attached
bit 13 not used
bit 14, 15 number of printers
Memory Size
This service returns the totai number of kilobytes of RAM in the
computer system (contiguous starting from address 0) in the AX
register.
Software Interrupts:
12 hex (18 dec)
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