@Fx51LP308, first started off with punch cards.
As did I. What a PITA as the cards would load slow and if you made one tiny mistake, the card was ruined and you had to start over again. Thankfully, later on, they upgraded the keypunch machines to where you could enter the line electronically and correct any errors, then press "punch" and it would punch the card and feed the next blank quickly. Of course, after I left, they went to on-line terminals. No more punch cards needed.
For the DOS/VS machine it was strictly batch and it was cool to see how the system would read cards individually (in the "BG" partition) and in "spurts." Of course, when we implemented VSE/Power, it read the entire card file in one swoop, placing it on the "reader" queue to be executed.
One of my last batch job stream had 34 programs which did an accounting conversion. Could only run that at night because of limited resources. Went to the control room to shut every job down so mine could run.
I was one of the student operators for my Univ's "Administrative" Data Processing dept (that did all the business stuff - as opposed to the Academic mainframe dept. that did the educational "number crunching" and class work stuff). 1st shift (8a - 5p) was for all the all the University's general production work (payroll, Univ. Registration systems, Grade collection and reporting, etc. etc.). The 2nd shift (the one I worked - 5p - 12mid) was all the processing for the Univ. Library (catalog cards, book notices, etc, etc.). Printing Catalog cards and some of the sheets was interesting as we had to change the text train on the IBM 3203 printer to the "ALA" library text train cartridge (only two character sets) so it took more time to print things. You had better ensure you aligned it right! Shortly after I left, the Univ. bought the library its own IBM 4331 (and the ADP center a 4341). It does all the library processing, and they moved more of the "regular production" work onto the 2nd shift as it was getting way too large to limit it to 1st shift. The 3rd shift (12mid - 8a) was strictly for processing "Alumni" related things (contribution reporting, etc.). Only one operator at a time. And that was because (as I discovered later) the Alumni processing was the most confidential thing the center processed. You'd think it was the "Payroll" or the "Registration/grade databases" but nope! Alumni contributions were the most confidential thing they handled.
Last job we had MVS/XA, 4 mainframes. That was in 2019 when I retired. I was doing CICS w/ DB2 database. Others were doing Oracle database.
At my last Mainframe job, we were also doing CICS/DB2, but we were using a CICS facilitaor/writer called "TELON." It helped you write things like tabled data in your CICS Maps, etc. At my "next to last" mainframe job, it was CICS without TELON and with IMS/DB DC. The "DB" part, at least.
