IBM 3708 Description page 209

The keyboard remains locked until the print operation is completed. When the print
operation is completed, the keyboard unlocks according to the keyboard Restore in
the WCe. The Pri nter Busy message is cleared, and the print ID replaces the
Printer Printing symbol.
To perform the host-initiated local copy described above, the host program must
send a write-type command with the Start Print bit turned on in the WCC as an
RQD chain or as an RQE, CD, EB chain. Otherwise, the synchronization may be
lost or the request rejected with response OS43.
Printer Busy Condition:
If after performing the display screen update operation, the
370S finds that the connected printer or all printers in the selected print class are
busy with other local copy operations, the print request is queued. The Pri nter
Busy message is displayed. The DEV CNCL key can be used to cancel the
host-initiated requests in the queue.
Because the 3708 uses "between-bracket printer sharing," if the selected printer or all
printers in the selected class are found to be "in brackets" with the PLU, the copy
operation is refused. After the screen update is complete, the 370S responds to the
print request with a negative sense code of OS07, printer busy. Once a print request
has been refused in this way, the 3708 sends LUSTAT of 'OOOlBOOO' to the PLU
when a printer becomes available. (Only one LUSTAT is returned per LU,
regardless of the number of times the host LU may have requested a local print
operation.) The host may choose not to wait for the LUSTAT but to continue with
other display work. The 3708 sends the LUSTAT when a printer becomes available,
whether or not the host LU has gone on to perform other display work.
Printer Not Working Condition:
If no printer is functioning at the time the local
copy request is processed, the Pri nter Not Work i n9 message replaces the Time
message. The Write command is responded to with a negative response code (OS2F),
permanent printer error.
If the PLU transmits any FM data request to the display and the Printer Not
Working symbol has not been cleared by an operator RESET, the FM data request
removes the Printer Not Working symbol.
If the printer malfunctions during the print operation, the Pri nter Not Worki n9
message is displayed. The print operation terminates, and the Write command is
responded to with negative response code (OS2F). The keyboard remains locked and
the system waits for some recovery action from the host.
Note that any FM data requests from the PLU clears a Printer Not Working
symbol. This requires careful planning by an installation in the use of host- and
operator-initiated printing.
Local Copy Printed Format
The 370S sends a CR and LF sequence to the printer at the beginning of each screen
copy. The data in the screen image is printed as if it were an LU type 3 formatted
printout using SO-character lines. The following restrictions apply:
• The data is scanned a line at a time. If a line contains one or more data
characters (including Space, NL, EM, and CR) in a display/print field, the line is
printed and a line feed is performed. To produce a blank line, at least one space
character must be present.
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IBM 3708 Description