IBM 2265 Manual page 34

I/o Channel Sequences
and Responses
EOT }
2845 Address Addressing
General Address (Hex = FF) Sequence
General Poll Command (Hex = 40)
I
I
I
I
I
I
.1
I
No Response
STX*
Text
ETX
LRC
STX*
EOT
SOH*t EOT*t
ACK
NAK
1
I
I
I
J
No Response
I
I
No Response
I
I
STX
Etc,
l.:egend:
SOH
I~
1
I
EOT
I
1
* General Poll must be reinitiated for same 2265, if Printer is attached,
to assure receipt of a message pending at the 2265.
** Indicates printer-buffer overrun.
*** CAN is transmitted only if the 2845 detects an internal parity
error after the ENTER key is depressed but before the message
text is completely transmitted.
tSOH or EOT response from I/O channel to a message ending in
ETX/LRC does not restore the 2265 keyboard, c'lear the SOM symbol,
nor extinguish the ENTER indicator. The ENTER operation is
still pending.
tsee "Error Recovery Procedures" for further I/O channel responses.
Figure 8. General Poll, Sequence/Response Diagram
34
I
EOT
2845 Sequences
and Responses
L
STX
(Negative Printer Address
response ETX
to Poll) LRC
:
Em
I
ACK
NAKt EOT** t
I
STX
2265 Address
Text
CAN***
ETX
LRC