I was lucky enough to sit just outside the mainframe room. I actually used to have to go and hand tapes to the operators to load vendor patches and updates.
Most of the guys didn't go in there much. However, one summer, we had a summer tape hanger job go to the daughter of one of the head office guys. She was a real cutie and very friendly. Suddenly, every guy on the floor had to go in to deliver tapes...and watch the job to make sure it ran.
The best part was that I was always in there, and she would talk to her friends on the phone about all the "dirty old men" that came in to flirt with her.
Started out in Vo-Tech (1973) on a Univac 9300, our DR (backup) system was an IBM accounting machine, every RPG program written for the Univac had to be wired for the accounting machine, my first job was working for Sears Eastern Territorial Office in St. Davids PA, the first IBM mainframe I "worked' on was a 370/158
Joined: 26 Jul 2006 Posts: 30 Location: Des Moines, Iowa
My first years were with Burroughs (UNISYS) mainframes starting in 1973. Early days using punched cards, then Burroughs terminals writing COBOL, UPL/SDL, etc. It was a fun time. I haven't seen a mainframe since 1998.
The first one I worked with and saw was the IBM 360. Then went to IBM 370/168, IBM 4341, 3081 & 3033, Hitachi NAS XL/100, Teradata, IBM 3090-XA/ESA, IBM 9672 / X37 CMOS.
The funny thing is I have no idea what mainframe I'm working on now and I've been consulting here for 8-years. It use to be sooo important when I first started as a mainframe developer but I don't seem to care now.
Mainframes use to be huge but now they look like filing cabinets. Servers take up the floor space now. Then again, a mainframe is just a "server" too.
During my initial training, they had an actual mainframe with them, and we were given the grand tour. Of course, we were not allowed to go into the room, just shown from outside through the looking glass so to say.
Joined: 30 Nov 2013 Posts: 664 Location: The Universe
IBM 3800 - I remember it well. For the time it was an amazing piece of hardware.
I've never seen the inside of a 3900. I suspect it's much the same as the 3800, especially the paper path.
You want to see a real Rube Goldberg device, the 3900 Duplex printer has to be seen. At one level, it's 2 3900's, at 90 degrees to each other. The paper comes out of the first 3900 near the floor - the old stacker is no longer used, it's flipped over over a roller bar set between the two printers and disappears into the second 3900.
But wait, there's more!
The paper for the first 3900 is a gigantic roll of paper. It starts out about 1 1/2 meters in diameter. The roll is quite heavy; it's mounted on a special feeder. I never saw the process to change to a new roll of paper.
At the output end is a gadget to burst the pages - yes, the final output is cut sheet. I don't how often it jams up, but it must be a mess when it does.
A roll-feed was available for the 3800, as well as a Burster-Trimmer-Stacker.
You could even spool-to-spool and then use a standalone BTS.
I don't know if those were from IBM or third-party. I suspect third-party.
The "hot fuser" technology in the 3800 meant that there were rigorous requirements for the paper stock and forms design. Like a pre-printed vertical line could only be a certain width, the paper had to contain a certain amount of humidity, and expel only a certain amount of paper dust.
Get all those wrong at once and you consumed the annual stock of fuser-rollers.
When competing cold-fuser printers appeared, where you could toss any junk in and even print on labels, and the printers were half the size (which is important when you saw how big a 3800 was) and which needed less power, less cooling, less maintenance... and could also be attached to a PC (1984-style PC) with a 6260bbpi tape-machine reading an unloaded spool-file...
Joined: 30 Nov 2013 Posts: 664 Location: The Universe
To me, one of the more amazing things about the 3800 was you could run old style "large" computer paper through it, though I never encountered or heard anyone doing that. As far as I know most people ran 8 1/2 inch by 12 inch paper (or its international equivalent) through it.
I knew the 3800 and 3900 had pretty high standards for paper quality. My employer when we got the 3800 was infamous for running really trashy paper through 1403s and 3211s. One of my better JES2 mods when I worked for them was a mod to print stuff over the paper fold to make it easier to find and separate jobs. It did such a good job it broke their trashy paper on the printer, so it was never used. But they knuckled under and ran acceptable paper through their 3800s.
Mr. Woodger - I never knew about the roll feed and BTS for the 3800, though now that I think about it I'm not that surprised. I'm pretty sure they came from a third party rather than IBM.
The site did a lot of printing. Two 3800s, later three, printing almost all the time, except for maintenance periods.
We used a wide variety of sizes of paper. Producing a lot of letters per day, you could cut printing time in half by printing "two up" - use wide paper (pre-printed letter-headed), two letters per page. These would go to the mailing room, and go into one of the magnificent machines there, which stripped the sprockets, split the paper, folded the letters, and then fed alternately into window-envelopes.
You could get up to eight "things" into an envelope, which could be multiple letters to the same addressee, or inserts (advertising) and even a reply-paid return envelope. The output "hopper" was a postal sack. When full, it was tied-off and taken to the loading bay for a Post Office truck to collect.
The 3800s were very reliable, but did need regular maintenance periods. I only remember one failure of one printer (came in and looked at the queues, still a mass of Production printing to be done, meant we got no development printing until the afternoon).
I think our two-up mailings were on 16- or 18-inch wide paper, 12 inches deep. With custom FCBs, we could have many "typefaces" and symbols available.
The machine-room was quiet and cool. Just the CPUs and tape drives (16). The DASD was all in a separate room, and that was noisy if you went past when someone was going in (two TB of DASD by the time I left in '85).
The print-room was a great place to visit in the winter. Warm. Noisy. Chunk-chunk-pause from the 3800s (2 1/2 feet per second). Plus the line printers. If your hands were cold in the morning, stick them between newly-printed output from the 3800s. Toasty in no time.
The mailing room was very noisy and ambient (loading-bay doors often open). When 3800 paper stock arrived it was stored in a closed room, and then the expected amount would be taken out (about three times a day) to come up to room temperature/humidity. I think this staging process took about a week.
Found that out when we arranged a delivery of special paper for the day we needed it, only to be kicked for not allowing for it to stand around for that time.
I still have my "3800 Forms Design Guidelines" Ruler. A magnificent 17-inch thing, with sprocket-holes, inches, centimetres, sixths, eighths, tenths and twelfths. IBM supplied a load of them when the second 3800 was delivered.
If paper-dust accumulated on the fuser-roller, bang. If toner accumulated on the fuser-roller, bang. 350 sterling each. On our nightmare print-run (with that delivery, with a vertical "ribbon", which the designer said didn't count as a vertical line, but which contained within it a vertical line about six mm wide, cheap paper full of dust) we went through a fuser-roller per box of 2000 sheets, including a 200-page "fuser-roller cleaning" print per box, until we had to switch the printing to an external site (the people who supplied the paper, and had cold-fuser lasers, and who took "paper suitable for a laser printer" to mean paper suitable for their laser printers).
It was amazing what they could print on those machines. As well as half the size, they were slower, half the speed or so, but were much cheaper, and required much less maintenance and could run with no problems using really cheap paper (compared to the 3800). Labels, semi-glossy, multi-coloured with no restrictions. When I arrived they were printing Bingo Cards on thick paper with a scratch-off security patch and a decorated Christmas tree image, with "scratch-and-win" patches for the baubles. These were web-to-web (so, that massive roll, these were probably about 6ft diameter, feeding into the printer, and rolling up after printing) which were then moved by fork-lift. (The web-feeders we had took much smaller rolls. They weren't really used much, and I think they were a bad purchase on that basis. They had a reputation on the 3800s of causing more paper wrecks than fan-fold paper).
After my visit (carrying the spool tapes) to the printers, I was debriefed by the Operations Director. "Oh my good, I've just ordered a third 3800" was his response. Shortly after I left the company a few months later, they extended the print room and acquired three cold-fuser printers. I got zero commission :-(, as ever.
Talking of paper-wrecks, when they happened, you basically lost 20 pages of output, so the ops would "backspace" for 20 pages on restart. Of course, a couple of times the print job had actually finished when the wreck occurred, but the pages were mangled, and a re-run of the job was required to print the final pages.