TRANSFER Programming Manual

Language Considerations
TRANSFER Application Components
2–4 40970 Tandem Computers Incorporated
A client can be either a stand-alone client that operates as an entire application or a
dependent client that is actually a component of a larger application. Examples of
stand-alone clients are:
An electronic mail system such as the PS MAIL application supplied by Tandem
An online central filing system where packages are deposited by some
correspondents to be read by others
An application that reminds correspondents of events scheduled to take place on
certain days. With this type of application, correspondents might scan a folder for
Thursday, July 29th and find packages alerting them to various meetings
scheduled for that day; or the application might use delayed delivery to
automatically alert correspondents to imminent events whenever they log on.
Examples of dependent clients are:
Applications not originally designed to use the TRANSFER delivery system. In
such applications, the TRANSFER delivery system might be almost invisible to the
users. An example is a warehousing application where the user presses one
function key to review an invoice and another to transmit the invoice to a remote
node.
Applications involving PS MAIL. In some cases, the client might invoke PS MAIL
to perform various functions, usually by means of menu-screen entries. In other
cases, PS MAIL might call the client to perform some specialized function such as
formatting special interoffice memos or invoices. Specific information about
clients that interact with PS MAIL appears in Appendix A.
Language Considerations Most clients are written in SCREEN COBOL as PATHWAY requesters that execute in
PATHWAY terminal control processes (TCPs). You can also write clients in
FORTRAN, COBOL, TAL, Pascal, or C. If you use these languages, however, you lose
the ease of coding IPCs that is inherent in SCREEN COBOL and you lose the resource-
management capabilities of PATHWAY.