IBM 3708 Description page 213

The 3708 has no control over this type of occurrence. All data buffered in the 3708
for the printer would be discarded when user X's session is lost; but output buffered
in the host is beyond the control of the 3708.
How the 3708 Routes Data
The 3708 uses the START PRINTER and STOP PRINTER sequences from the
terminal control section of the terminal table to route data to either the display or
printer as appropriate. Input from, and output to, the display is given priority
whenever possible, although certain LU type 1 data streams may generate large
printouts before display data is processed. Response time for either device is, of
course, affected by data transfer to the other.
If RECEIVE
XONjXOFF
is enabled for the port through the configuration, receipt
of XOFF (DC3) from the device suspends transmission to both the printer and the
display.
All input from the device is assumed to be display input. This means that the
printer input sequences (Hold Print, Enable Print, Cancel Print, PAl, and PA2) are
not available. However, the terminal operator can affect the data transfers; this is
described in the next section.
How the Operator Can Control Where the Data Goes
The terminal operator can use the Suspend Display, Enable Display, Suspend
Printer, and Enable Printer keyboard sequences to alter the way the 3708 sends data
to the two devices. For example, to allow output to the printer and prevent display
output, the user would enter the Suspend Display key sequence. This facility can be
used when users notice that a printout is interrupting their display sessions too often
and wish to force the printout to finish. To allow display output again, the user
must enter the Resume Display key sequence.
Alternately, the user may prevent printer output temporarily by entering the Suspend
Printer key sequence so that output to the display can finish. Entering the Resume
Printer key sequence allows output to be directed to the printer from the 3708 again.
Special Information About Using the IBM 3101 and Hazeltine 1500
Although the IBM 3101 does allow data to be sent to a printer attached to its
auxiliary port, remote control of the auxiliary port is not permitted. As a result,
there are no START PRINTER and STOP PRINTER sequences that the 3708 can
use to direct subsequent data. To route output to the auxiliary port of one of these
terminals, the user must manually select the auxiliary port. For this type of device,
the four keyboard sequences - Suspend Display, Resume Display, Suspend Printer,
and Resume Printer - are used as follows:
• When the user wishes to direct output to his auxiliary port, he must:
1.
Enter the Suspend Display key sequence to halt all output from the 3708.
2. Manually switch the display for auxiliary port operations.
3. Enter the Resume Printer key sequence to notify the 3708 that printer data
may be sent.
• When printing is finished, or the user wishes to suspend printing, the user must:
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IBM 3708 Description
1.
Enter the Suspend Printer key sequence to halt output from the 3708.
2. Manually switch the display for display operations.
3. Enter the Resume Display key sequence to notify the 3708 that display data
may be sent.