IBM 1 Series - Page 107

cv
CcO0-VE
VD
User’s attachment
Isolated receive inputt+
or
Nonisolated receive input—
EIA received data in
TTL received data in
Signal ground
SSS closed = data mark or
—TTL data out
SSS open = data mark or
+TTL data out
EIA transmitted data
EIA data terminal ready
SSS/TTL write control
SSS/TTL read control
Current driver,
current = mark
Current driver,
current = space
Frame ground
Key:
TTL = transistor-transistor logic
Receivers
and
drivers
Teletypewriter adapter feature
A
EIA = Electronic Industries Association
SSS = solid state switch
IPL = initial program load
Figure 4-1.
A
TTTEPERE
LT)
Block diagram of teletypewriter adapter feature
I/O channel
Receive Receive TT
data ) buffer )
register register
Drivers Data bus
and
receivers [++
Transmit
|
att KC |
register tL
J
Command
decode |
Drivers Address bus
and
receivers le >
Address |
decode ) io
Address IPL Primary / | Cycle-steal status bus
Jumpers control alternate
(8) jumpers Lo ~