Tandy 1000 Technical Reference Manual

IBM PC
IBM PCjr
TANDY l~~~
DATA ~~61 - PORT B - READ OR WRITE
~~61 - PORT B - READ OR WRITE ~~61 - PORT B - READ OR WRITE
BIT
~
1 = 8253 GATE #2 ENABLED
SAME
SAME
BIT 1
SPEAKER DATA OUT
SAME
SAME
BIT 2
1
=ENABLE READING
1
=ALPHA (GRAPHICS) NO FUNCTION
CON
FIG SW 13 THRU 16
(I/O CHAN. ROM SIZE) OR
~ =ENABLE READING
CONFIG
SW 12 (@PC~ - PC3j
BIT 3
1
=CASSETTE MOTOR OFF
SAME
NO FUNCTION
BIT 4
~ =ENABLE RAM PARITY
1 - DISABLE CASSETTE MTR
NOT USED
RELAY
INTERNAL BEEPER
BIT 5
~ =ENABLE I/O CH PARITY
SPKRSW ~
SOUND CONTROL ~
BIT 6
~ =HOLD KEYBOARD CLK LOW SPKR SW 1 SOUND CONTROL 1
BIT 7
~ =ENABLE KEYBOARD
1
=KEYBOARD CLEAR
1 =KEYBOARD CLEAR
1 =CLEAR KEYBOARD AND
ENABLE CON
FIG SW 1-8
o
o
o

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