60
The Upper Data PCA state contains these registers:
Name
Size
Radix
Action
IBUF
16
8
Input buffer; holds channel status
OBUF
16
8
Output buffer; hold channel select
The Lower Data PCA state contains these registers:
Name
Size
Radix
Symbolic
Action
CTL
1
2
Control flip-flop
FLG
1
2
Flag flip-flop
FBF
1
2
Flag buffer flip-flop
STA [0:20]
16
8
Receive channel status, channels 0-20
RPAR [0:20]
16
8
Receive channel parameters, channels 0-20
XPAR [0:15]
16
8
Transmit channel parameters, channels 0-15
RBUF [0:20]
16
8
Receive channel buffers, channels 0-20
XBUF [0:15]
16
8
Transmit channel buffers, channels 0-15
RCHP [0:20]
1
2
Receive channel character present, channels 0-20
XDON [0:15]
1
2
Transmit channel done, channels 0-15
BDFR [0:15]
1
2
Receive channel break deferred, channels 0-15
TIME [0:15]
24
10
Transmit channel time, channels 0-15
The RBUF and XBUF registers default to single-character format display and entry but may be overridden with
numeric-format switches, if desired.
4.10.2 Control PCA
The Control PCA provides the Request to Send (CA) and Data Terminal Ready (CD) control lines, and the Data Set
Ready (CC) and Carrier Detect (CF) status lines for each of sixteen terminals or data sets. The modem controls
model the Bell 103A data set without ring detection.
A new Telnet connection sets Data Set Ready and is established whether Data Terminal Ready is set or not.
Control PCA device options that may be specified are:
Option
Action
SC=<n>
Set the interface card select code; default is 42
The Control PCA is usually installed in the slot above the Upper Data PCA, but this is not required.
There are no Control PCA units or unit commands.
Control PCA device configuration may be displayed with the following commands:
Command
Action
SHOW MUXC
Display the device configuration
