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Message Broadcast Facility

IP.com Disclosure Number: IPCOM000038995D
Original Publication Date: 1987-Apr-01
Included in the Prior Art Database: 2005-Feb-01
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Coyne, LE: AUTHOR

Abstract

The program's function is to give MVS (multiple virtual storage) operators the ability to send messages to 3250 and 5080 graphics terminals running CADAM*. CADAM already provides an interrupt routine to allow operators to use the CADAM STOP and NEXT commands. This interrupt is modified to add a third command called MSGS. CADAM also already provides a monitor program which has the interrupt function and attaches the interactive CADAM module. When the CADAM monitor program gets on MSGS interrupt, the broadcast program will be called. The broadcast program finds the necessary graphics address and buffer information used by CADAM so that the 3250 and 5080 can be shared. The message sent with the MSGS command is then written to the graphics buffer at the location CADAM uses for its third line of data.

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Message Broadcast Facility

The program's function is to give MVS (multiple virtual storage) operators the ability to send messages to 3250 and 5080 graphics terminals running CADAM*. CADAM already provides an interrupt routine to allow operators to use the CADAM STOP and NEXT commands. This interrupt is modified to add a third command called MSGS. CADAM also already provides a monitor program which has the interrupt function and attaches the interactive CADAM module. When the CADAM monitor program gets on MSGS interrupt, the broadcast program will be called. The broadcast program finds the necessary graphics address and buffer information used by CADAM so that the 3250 and 5080 can be shared. The message sent with the MSGS command is then written to the graphics buffer at the location CADAM uses for its third line of data. The scope is beeped to get the CADAM user's attention. The program utilizes the IBM program product Graphics Access Method (GAM). The GAM routines permit the use of an actual data control block (DCB) address instead of a DCB name. Because CADAM has already opened the DCB, the GAM routines execute the functions of writing the message to the graphics buffer and beeping the terminal to get the user's attention. A program outside of CADAM's environment would not be able to get the DCB address. The program would also not be able to open the graphics device using its own DCB because CADAM has exclusive control of the device. Hence, the message progra...