Mainframe, MVS and zOS Discussion

Hi,

I was asked t work on a Tandem Cobol project and recommend some performance improvements. Actually, have never worked on Tandem Cobol but have experiece in to mainframes and entrprise Cobol. Do you know what is the difference between Tandem Cobol and the one used in mainframes? Can it be readily picked up. As of now I have asked for some time.

You'd need to find out if the compiler in use is to the COBOL 85 Standard, or the COBOL 74 Standard. All the Tandem COBOL I've seen is '74. Enterprise COBOL, which is 85, is quite different from that. Easy to go from 74 to 85, not so easy to go the other way. No scope-terminators (END-IF and suchlike), heightened importance of full-stop/period in the PROCEDURE DIVISION. If you find some old Enterprise COBOL Migration Guide it consider references for changes to OS/VS COBOL, it should give you some ideas, as will search-engineing for differences between COBOL 74 and COBOL 85.

Easy to go from 74 to 85, not so easy to go the other way.

You meam to say that going from Tandem COBOL 85 to Enterprise COBOL 74 is easy but not otherwise?

No! He means, I am pretty sure, that going from the 85 standard to the 74 standard is difficult because 74 is not compatible with 85 but 85 is compatible with 74.

nicc is correct. Other than minor things, COBOL 74 program will compile with a COBOL 85 compiler.

If you are writing code to make use of COBOL 85 (and why wouldn't you?) that code stand a snowball's chance in hell of compiling with a COBOL 74 compiler.

If the Tandem COBOL in question is COBOL 85 and you are using Enterprise COBOL, then you'd not face many problems (Tandem COBOL programmers tend to make a lot of "system calls", and copybook library use looks different, but they're not big things).

If the Tandem COBOL is 74, then you'd be starting your training again.

The machine environments are entirely different. A Tandem Non-Stop (now HP anyway) is a big mini-computer, not a Mainframe. If you touch a key on the keyboard, the computer itself knows about it, unlike a Mainframe. You can pick up enough in a couple of days to be productive, but it would take a while to become proficient.