Tandy 1000 Programmer's Reference Guide

Appendix C I MS-DOS Memory Map
19 1 byte - used to store ALT keypad
1A
1c
1E 16 - keyboard buffer (enough for
entry
keyboard buffer
keyboard buffer
words)
1 word - pointer to beginning of the
1 word - pointer to end of the
15
- typeahead entries
The structure and usage of the clock service routine is as
follows:
HEX Offset From Length and
Segment
00400000 Intended Use
6CH
6EH
70H
1 byte - Twenty four hour rollover
1 word - Lease significant 16 bits of
1 word - Most significant 16 bits of
clock count
clock count
flag
233

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