|address,||synth (german),||links (german),||hiking (german),|
systems programmer OS/390 (earlier spoken "MVS"). Sometimes I work on RS/6000 UNIX systems (exactly AIX, it´s the IBM UNIX for their RISC-Computers). I´m the same for the computers as the mechanics for cars - in the data processing world.
If you want to look deeper on this kind of computer, I recommend you a little gimmick called Hercules emulator. That´s a S/390 computer on your PC ;-) It runs directly under LINUX and with the help of CYGWIN under Windows You have to download and install both pieces. I did so and here are my experiences installing and operating Hercules, booting OS/390 and LINUX/390. Be shure to have a 500MHz machine or more !
For the installation, you need a MVS or OS/390 or zOS -
if you want to dump your sysres and other dasd in a "downloadable" and compressed format, you can download the
CCKDDUMP program from my website.
Store the above file to PC, upload it to your MVS with RECFM=F BLKSIZE=1024 (all binary) and run the
IBM TRSMAIN utility
to unpack the file to a loadlib, then run the jobs described in my installation experience.
You will get another version from the SHARE-Tape Number CBT541
Some people like to ask me:
"What does a systems programmer really do the whole day ?"
(even my boss), so I try to describe you a normal working day:
In the morning, Mr. Haag enters the
after a hard travel with the city train.
Forgetting his bananas (yellow things to eat), he buys his "Brezels" (kind of bread looking like a "8") in a little bakery.
|Doesn´t come too late, doesn´t need bananas but works 24 hours a day - the cartridge robot.|
Armed with this stuff, he opens the door to the office with his magnetic card and tries to get to his desk, where his boss is awaiting him - to shake hands...
An error in one of many programs of the system (things like copy programs, language translators and other utilities) leads him to look into the IBM-Database, maybe another customer has got the same problem and a solution exists. If he won´t find anything in the database, he has to call the hotline to report the problem.
|...our computer with three processors and 1 Gigabyte RAM awaits me too...|
Gotcha - a so called "PTF" was made available for the error, that´s a correction for the error, which he can
download to his computer and bring it into the system with a software tool. It replaces the erroneous part of the original program.
Some corrections are sensitive to the running system, he must come on the weekend, when the computer is stopped for some minutes.
Now, he got magnetic tape cassettes with a new program...he has to read the documentation to install the tape (copy the programs onto harddisks).
|Today, we use cartridges instead of the old "reel-tapes" with a capacity from 400 MByte to 60 GByte.|
But he is interupted by an application programmer - the peoples which writes the "normal" programs for the "normal" users ;-) -
got an error with the translator program (so called "Compiler").
Because of the importance of the new problem, we lay the magnetic tape aside and look on the translation lists (Don´t think of paper, today, these things are stored on harddisks) to separate the translator error. Oops, a wrong program library - we inform the programer about the solution. Time to continue the installation...
You don´t have to think of an installation as a "copy-only" task. The implementation of a complex product has to be planned (especially used resources, runtime, education of users aso.) exactly to avoid an unplanned increase of costs. As real professionals, we did these things earlier - not always, but always a little more...
|This is the place where we keep our direct accessed data, a box full of harddisks configured as a RAID-cluster: if one disk crashes, no data is lost. Capacity actual 1.5 Terabyte (1,500 Gigabyte).|
Another guy, another break - a job is broken: our computer not only runs online systems for terminals but also "batch jobs", programs called by scheduling systems with an embrassing language called "Job Control Language". In the job control language, you define the name of your program but also the name of the datasets which are to be used. It´s some kind of AUTOEXEC.BAT for the mainframe computer...
Ok, we look at the protocol, the "job log"...think...brain...yes, the output dataset is to big for the specified harddisk. Hmm...shall we use another harddisk ? But...the control listing shows only the same records...think...it seems to be an error of the programmer - so back to the other department, they have to rework the program !
After lunch, we prepared our interupted installation although an incomplete documentation, although wrong samples - late in the night, we leave the office with the head high but the stomach low...