Having fun diving back into MVS. Even though my professional career was with DOS/SP/VSE/ESA bla bla bla. Since I already did the sys programmer thing, there…already scratched that itch, frankly more interested in just using/programming on a IBM mainframe, than administrating/fixing/patching. And the tk4- emulator seems like very a nice/useable MVS 3.8j OS, complete with TSO and a ISPF “like” environment to work in. The DOS emulator environment seems like a lot of work to make really useful/productive. Also I’ve forgotton so much DOS/SP/VSE/ESA that it’s a lot of effort/work to “play” in. So if I’m going to relearn mainframes I might as well concentrate on MVS. Which, by the way, bonus, I’ve been told is still very similar to z/OS, the current IBM flagship OS. Also all my mainframe schooling was in MVT which is the father of MVS. So the JCL is similar. So, I’m sure some of it is buried in the deep recesses of my mind. MVS and now z/OS, is, and has always been the king of IBM mainframe OSs. COBOL programming is largely the same, ASSEMBLER other than the Macros is also largly the same using the S/370 instruction set, with advances.
Ok, so I with the help of a Moshix Youtube video, successfully compiled/executed/viewed my 1st COBOL program. Check out his channel for other helpful Mainframe videos. Pretty much followed his video…except for one thing. I didn’t see my COBOL JOB output on he OUTLIST screen. Then I noticed “(USE ST * FOR ALL JOBS)” at the bottom of the screen. Sure enough I typed that in at the COMMAND prompt…and there it was! Very satisfying to see this. Although I can’t claim to fully understand the whole MVS process right now, it is very reminiscent of what I did on MVT at school in the late 1970s…except more advanced. What I wouldn’t give, back then to code on a full screen editor and submit and view my job right where I sat! However, as old as MVT is, many utilities, such as IEBCOPY IEFBR14, are STILL the same!
Another reason to go MVS rather than DOS…as if it wasn’t enough getting DOS/VS running in VM…which I did and was able to use VM for my interactive environment including submitting JCL to DOS…I couldn’t even successfully compile a COBOL program out of the box because of a DASD issue. Really? There is a solution, however why wasn’t DOS/VS packaged up in a way that common tasks that a programmer would do back then…like say COMPILING A COBOL PROGRAM? No thanks…it’s quite enough to learn how to use a WORKING IBM mainframe OS, without starting off fixing and patching things. Looking at the tk4- config file…DASD devices 3330 and above, such as 3350, 3375, 3380 and 3390 are already recognized by the OS. If you want to learn an IBM mainframe OS then you might as well start with IBMs flagship OS, because DOS/VS, as supplied, is the biggest advertisement for learning MVS 3.8j (as implemented by tk4-). No wonder the MVS guys made the big bucks. The Hercules/tk4- people should be very proud of the work they’ve done!