explicit alternate program communication block

modifiable alternate program communication block

data communication program communication block

telecommunication-program program communication block

generalized sequential access method program communication block

program communication block

database program communication block

alternate block

alternate communication

alternate communication facility

tow-way alternate communication

two way alternate communication

two-way alternate communication

alternate program

“Friend Communication” Program

bidirectional communication program design

C serial communication program

channel program block

communication program