Radio Shack TRS-80

Interface
Specifications
Cassette
Suggested
Input
Level for
Playback from
Recorder
Typical
Computer
Output
Level to
Recorder
Remote
On/Off
Switching
Capability
2 V
peak-to-peak
at a
minimum
impedance
of
360K ohms
800 mV
peak-to-peak
at IK
ohm
0.5 A
max at 6
VDC
DIN
Jack Pin
Connections
(See Figure
1)
1
—
Remote
2
—
Signal
ground
3
—
Remote
4
—
Input
from
recorder's
earphone jack
5
—
Output to
recorder's
Aux or Mic
jack
Video
Signal
DIN
Jack
Pin
Connections
(See
Figure
1)
1
—
+5
VDC at
50
mA
2
—
Not
used
3
—
Not
used
4
—
Video
signal, 1 .4 V
peak-to-peak,
0.4V
negative sync, 75 ohms
5
—
Ground
Figure 1 . Pin
Connections
for TAPE and
VIDEO
DIN
Jacks
(viewed from
rear of
keyboard assembly)
Pin Connections
for
Expansion
Port Edge
Card
(See Figure
2)
SIGNAL
P/N
NAME
DESCRIPTION
1 RAS*
Row
Address Strobe
Output
for
16-Pin Dynamic Rams
2
SYSRES
*
System
Reset
Output,
Low
During
Power Up
Initialize
or
Reset
Depressed
3
CAS*
Column Address
Strobe
Output for
16-Pin
Dynamic
Rams
4 A10
Address
Output
5 A12
Address
Output
6
A13
Address Output
7 A15
Address
Output
8
GND
Signal
Ground
9 All
Address
Output
10
A14
Address
Output
11 A8
Address
Output
12
OUT*
Peripheral
Write
Strobe
Output
13 WR*
Memory Write
Strobe
Output
14
INTAK*
Interrupt
Acknowledge
Output
15 RD*
Memory
Read
Strobe
Output
16
MUX
Multiplexor
Control Output
for 16-Pin
Dynamic
Rams
17 A9
Address
Output
18 D4
Bidirectional
Data
Bus
19
IN*
Peripheral
Read
Strobe
Output
20 D7
Bidirectional
Data Bus
21 INT*
Interrupt
Input
(Maskable)
22 Dl
Bidirectional
Data
Bus
23
TEST*
A Logic
"0"
on TEST*
Input
Tri-States A0-A15,
D0-D7,
WR*,RD*,IN*,OUT*,RAS*,CAS*,MUX*
24 D6
Bidirectional Data
Bus
25 A0
Address Output
26
D3
Bidirectional
Data
Bus
27
Al
Address
Output
28
D5
Bidirectional
Data Bus
29
GND
Signal
Ground
30 D0
Bidirectional Data Bus
31 A4
Address Bus
32 D2
Bidirectional
Data
Bus
33
WAIT*
Processor
Wait
Input, to Allow
for Slow
Memory
34
A3
Address
Output
35
A5
Address
Output
36
A7
Address
Output
37
GND
Signal
Ground
38
A6
Address
Output
39
+
5V
5 Volt
Output
(Limited
Current)
40 A2
Address
Output
NOTE:
*means
Negative
(Logical
"0")
True
Input
or Output
Mates with
AMP P/N
88103-1 Card
Edge
Connector
or
Equivalent
I 3
5
7
9
11
13
15
17
19
21
23 25
.27
29 31 33 35
37
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6 8
10 12 14 16 18 20
22
24 26
28 30 32 34 36 38
40
Figure
2.
Connection
points for
Expansion
-Port
Edge
Card
(viewed
from
rear
of
keyboard
assembly)
228