IBM 5150

+5V
74LS38
3.9K OHM
R
8253TIMER#2 to
OUTPUT
OR
o
0----------
.S78V
TO AUX
INPUT
O------------------~ •
. 075V
TO MIC
INPUT
GND
Figure 8. CASSETTE INTERFACE WRITE HARDWARE
+5V
I
+5V
I
4.7
I
KOHM
SN75475
RELAY
+5V-
CLAMP COIL
S
N/O
74LS38
C~.
CASSETTE
VCC
-
MOTOR
OR
IN
OUT
COIL
CONTROL
MOTO~O
ON
o
.----
VSS
COM
GNO
Figure 9. CASSETTE MOTOR CONTROL
2-20