gtpd2m0o | Data Communications Services Reference |
A 1052/3215 printer-keyboard attached through a multiplexor channel is the minimum CRAS configuration for this support. With this configuration, the 1052 must serve as both the PRC and RO system consoles so that operator initiated functions as well as unsolicited logging of output can be serviced on this single device. The operator has the ability at all times to preempt unsolicited output to the 1052 by pressing the request key. This causes an attention interrupt to be stacked in the device. This request is serviced when the output in process is completed, at which time the 1052 is conditioned to receive the input message and forward it to the host processor.
The minimum CRAS configuration for this support is a 3270 console, providing the user does not require a hardcopy log of system activity. Although the TPF system can survive without a system RO printer, the user is urged to provide one. The recommended minimal configuration is that a control unit (in addition to that of the native console, if one exists) be dedicated to TPF's system console support. This control unit can be used for the RO console, fallback system consoles, and fallback RO consoles. For information about console definition, see the CRASTB macro in TPF System Generation. All such consoles can be on the same control unit or on separate control units, but none may be on the same control unit as any other 3270 local device. All system consoles are supported as model 2 devices (1920 byte buffer), regardless of actual device characteristics.