Processing Binds; Internal Storage Requirements For Large Screens; Local Copy Functions With Large Screens - IBM 3708 Description

Processing BINDs
The BIND may specify default and alternate screen sizes. Byte 24 is examined, bit 1
is reserved. For a LU type 2, byte 24 is interpreted as follows:
Value Meaning
X' 00' Base Model 2, 24 x 80 screen size
EWA same as EW.
X' 02 ' Model 2, 24 x 80 screen size
EWA same as EW.
X '7E' Use row-column of bytes 20, 21 for the default size.
EWA same as EW.
X '7F' Use row-column of bytes 20, 21 for the default size, and use row-column of
bytes 22, 23 for the alternate size.
EW A puts 3708 into alternate screen size.
Internal Storage Requirements for Large Screens
The 3270 Model Emulation values affect the 3708 internal storage calculations.
Message Cl17 is displayed when the storage limit is exceeded:
Cll7 BUFFER CONSTRAINT EXCEEDED; Pm
+
2(PI)
+
2(P
4)
+
2(P
ls )
<
40 - 2(Pne)
where:
Pm The number of ports set for medium receive queue
PI The number of ports set for large receive queues
P
4
The number of ports operating as device class
=
4
Pis The number of ports enabled for model 3, 4, or S emulation
P ne The number of ASCII ports not excluded.
MLU operations are possible with large screen support, as long as all internal buffer
requirements are met.
LOCAL COpy Functions With Large Screens
When LOCAL COPY of a screen is initiated by either a host or a terminal operator
that is emulating modelS, the 3708 assumes that the Maximum Platen Length of the
printer is 132. If the physical platen length of the printer is less than 132, data may
be lost.
It
is recommended that local copy printers be grouped into classes based on
their configured platen lengths.
The 3708 does not check the page length. As a result, screen text may spill onto
more than one sheet of paper (depending on the screen size definition and the printer
page length).
Chapter 4. Protocol Conversion Mode
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