IBM 2265 Manual page 47

Table 7. Sample CCW Formats for Information Interchange Between 2845 and I/O Channel
I/O Channel Data
2845 Command Action Command Address CC Flag SLI Flag Byte Count
Specific Poll to
Send addressing sequence Write EOT X X 4
Display Station
Receive DS message
Read STX X X 964
Send STX/EOT Write STX X 2
Specific Poll Send addressing sequence Write EOT X X 4
to Printer
Receive positive response Read STX X X 3
Send Printer message Write STX X X Text plus 2
(STX and ETX)
Receive ACK Read ACK X X 1
Send EOT Write
EOT X 1
General Poll
Send addressing sequence Write EOT X X 4
Receive positive response Read STX X X 964
from Printer or receive
DS message
Send ACK Write ACK X X
1
Receive next message Read
STX X X 964
(if
any)
Send STX/EOT Write ACK X 2
Read Addressed Send addressing sequence Write SOH X
X
4
Full DS Buffer
Receive DS buffer contents Read STX X X 964
Send STX/EOT Write STX X 2
Write Addressed DS Send addressing sequence Write SOH
X X
4
Receive ACK Read ACK X X 1
Send DS message Write STX X X Text plus 2
(STX and ETX)
Erase/Write
Addressed DS
Receive ACK
Read ACK X X
1
Send EOT Write EOT
X
1
Write Printer Send addressing sequence Write
SOH X X
4
Receive ACK Read ACK X
X
1
Send Printer message Write STX X X Text plus 2
(STX and ETX)
Receive ACK Read ACK X X 1
Send EOT Write EOT X 1
Write DS Line Send addresSing sequence Write SOH X X 4
Address
Receive ACK Read ACK X X 1
Send DS message
Write STX X X Text plus 3
(STX, Line Ad-
dress, and ETX)
Receive ACK Read ACK X X 1
Send EOT Write EOT X 1
x
=
Flag bit set to 1
Principles of Operation 47