Tandy 1000 Technical Reference Manual

Tandy 1000
Technical Reference Manual
inter
8237A/8237~4/8237~5
A.C. CHARACTERISTICS-PERIPHERAL (SLAVE) MODE (TA = O"C to 7r1'C. vee = 5.0V :!:5%.
GND = OV)
Symbol Parameter
8237A 8237A-4
8237A-5
Unit
Min. Max. Min. Max.
Min.
MD.
TAR ADR Valid or es LOW to READ LOW
50
50 50
ns
TAW ADR Valid to WRITE HIGH Setup Time
200
150
130
ns
TCW CS LOW
to WRITE HIGH Setup Time 200 150
130
ns
TOW
Data Velid to WRITE HIGH Setup Time 200
150
130 ns
TRA
ADR
or CS Hold from READ HIGH
0
0 0
ns
TRDE
Oata Access from REAO LOW (Nole 3)
200 200
140
ns
TRDF
DB Float Delay from READ HIGH 20 100
20 100
0
70
ns
TRSTD Power
Supply HIGH to RESET LOW Selup Time
500 500
500 ns
TRSTS RESET
10 First IOWR 2TCY
2TCY 2TCY
ns
TRSTW
RESET Pulse Width
300 300
300
ns
TRW
READ Width
300
250
200
ns
TWA
ADR from WRITE HIGH Hold Time
20
20
20 ns
TWC
es HIGH from WRITE HIGH Hold Time 20 20
20
ns
TWO Data from WRITE HIGH Hold Time
30
30
30 ns
TWWS WrileWidth
200
200 160
ns
WAVEFORMS
SLAVE MODE WRITE TIMING
DBD-DB?
1------- TWWS ------1 ~__:_----'-"-''"''-
INPUT VALID
INPUT VALID
Figure 9. SiaM Mode Write
v
SLAVE MODE READ TIMING
cs~
F-----------------------:J[""
-
AO-~3 ~ ADDRESS MUST BE VALID K
.. ~--J1'-I----TAR-,-! =--=-~-=---~~TRD-E~~~~~-t~~_=e~~~-:m_:':-~3--
OBO-DB7 -------------F-lg-u-re-1-0-. -S-I.-ve-M-ode--Re-'-d-{ DATA OUT VALID
2-99
AFN-OOT89D

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