Vector 4 - Page 196

VECTOR 4
TECHNICAL INFORMATION
SIGNAL LOCATION DESCRIPTION
PACD U55-9 Active low; used as reset
PAEF U55-T7 Active low; used as clock fo
rgeneration of CAS
I0SEL U52-8 Active low; used as enable for I/0
communications and for US54 and
U55
P1¢1 U54-15 Active low; used as chip select for
timer (8253)
P123 U54-14 Active low; used as chip select for
timer (8253)
P145 U54-13 Not used
P167 U54-12 Active low; used to write data
| into regular memory map
P189 U54-11 Active low; used to generate chip
enable for tone generator
P1AB U54-10 Not used
P1CD U54-9 Used to generate a write enable
for UT73 .
P1EF U54-7 Used to generate a write enable
for U73 |
T# U97-10 Active — dependent on baud rate
T1 U97-13 Active — dependent on baud rate
T2 U97-17 Active — dependent on baud rate
2MCLK Ul112-4 Pulsating 2MHz square wave
Keyboard
TXD U96-19, J14-6 Active when TX data
RXD U96-3, J14-2 Active when RX data
09-01-82
7200-0001
V
4-7