Multiple Logical Unit Support - IBM 3708 Description

The 3708 supports the following input from a keyboard printer that is directly
connected to the 3708:
• Hold Print/Enable Print
• Cancel Print (LU type I SCS only)
• PAl and PA2 (LU type I SCS only).
Note: Keyboard printers operating in protocol conversion mode are supported as
output devices and must be defined as printers.
Up to 256 characters (8-bit data with no parity) can be used with an output-only
device operating in LU type I SCS transparency mode. (See "Transparent (TRN)"
on page 4-23 for more information on LU type I transparency.)
Multiple Logical Unit Support
A printer connected to an auxiliary port on a display that supports remote access to
its auxiliary port can be defined as a second LU on the 3708 port to which the
display is connected. The printer can then be used in system mode, local mode, or
shared mode. This support is referred to as multiple logical unit (MLU) support and
operates only in protocol conversion mode.
If a printer is connected to an auxiliary port on a display and is not defined to the
3708, the printer can be used only for screen copy operations that are initiated by
the user. The user enters a predefined key sequence that the 3708 echoes back to the
display.
Input from devices that are connected to the auxiliary port of a display is not
explicitly supported; any such input is assumed to be for the display.
1-10
IBM 3708 Description