Tandy 1000 Programmer's Reference Guide

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
= 40~25BW
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)
213

Tandy 1000 Specifications

General

Processor	Intel 8088
Processor Speed	4.77 MHz
RAM	128 KB (expandable to 640 KB)
Operating System	MS-DOS 2.11
Manufacturer	Tandy Corporation
Release Year	1984
Storage	Single or double 5.25" floppy disk drive (360 KB), optional hard drive
Sound	Tandy 3-voice sound
Ports	Parallel, Serial
Graphics	CGA (Color Graphics Adapter)
Graphics Modes	320x200, 640x200