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Tales of a Longtime Mainframer

By Destination Z posted Mon December 23, 2019 03:36 PM

At the IBM System z Technical University in Budapest in May, I gave a session where I told stories from my 45 years with the mainframe. Since it went over pretty well, I am sharing some of the stories with the wider audience here, starting with these from my very first days in the industry. Share your memories in the comments below, and they may be featured in a future mainframe memories blog post.

I was first exposed to computers when I joined IBM in 1969 as a 19-year-old computer operator. I knew absolutely nothing about computers—not even enough to go to IBM’s computer operator education. So I had to observe an experience operator and ask questions.

I watched the guy do what he called IPL, and a message came out on the big typewriter that was the console of the S/360 model 50, “Specify System Parameters.” He typed, “REPLY, ‘U.’ ” I found this strange, and he could not explain why that was the correct response. I realized that “REPLY, ‘U’ ” meant that the system should take the default action. Since the mind tries to find meaning in the phenomena it encounters, I came to think that “REPLY, ‘U’ ” meant “You decide” or “U decide.” I had not yet learned the word default in the sense of taking a default action or using default options.

My mentor found this interpretation funny but could not offer a better one. In the 45 years since then, I have not found anyone who knows the reason that a reply of “U” designates that the systems should take the defaults. Perhaps some reader knows the solution and I can put the question to rest.

After I was a teeny bit trained, I was assigned to do restores on an S/360 model 30. It had two tape drives and three disk drives (2311s with a capacity comparable to a floppy disk).

My job was to mount tapes and change disk packs as directed by the all-knowing OS/360. I had to put a deck of cards that were punched with what looked like something Sgt. Snorkel would say into the card reader and type “START RDR,00C” on the console typewriter. Then the all-knowing OS would read a card on the card reader and instruct me to mount a tape on unit 282 and place a disk pack into drive 191 (disk drives had removable disk packs in those days). After all the data had been transferred from the tape to the disk pack, it would read another card and ask me to mount a tape on the other tape drive and place another disk pack into the other disk drive. And it did this over and over, and I obeyed over and over until all the cards in the card deck had been consumed.

I needed to place the deck in the card reader again and type again on the console. This was fine until I dropped the card deck and had no idea how to put it into sequence. In a panic, I asked the lead operator for help. To my amazement, he put the deck back in good order in about four seconds. I was astounded at his genius. Only months later, when I learned a bit about Job Control Language and the IEHDASDR utility, did I realize how simple the task really had been. I felt sort of foolish. But this wasn’t the only time.

All of the new incoming operators in my department had to train on the model 30. I imaged that it was such a painfully boring assignment that the low man on the totem pole always got stuck with it. It was sort of a rite of passage. Another rite of passage was falling victim to a stupid prank. The IBM designers of the 1403 printer decided to notify an operator that it had run out of pin-feed paper by having the covering of the printer rise up and tilt back exposing mechanism through which the paper was fed. It lead to some unintended consequences.

When the current box of paper was almost out, some more experienced operators would come over to chat with the newbie. They’d stand by the printer and rest their coffee cups on the printer’s lid. Of course, new operator joined them and placed his coffee on the printer lid. Just as the paper was running out, the experienced operators would remove their cups. The new guy, of course, is totally startled when the printer cover suddenly starts moving and doesn’t get his cup off in time. It slides off the printer and crashes on the floor, much to the glee of the sadistic experienced operators. I fell for this prank, but I did not warn new operators, not out of any mean-spiritedness, but I just didn’t want to be the last fool to fall for this stupid trick.

Bob Rogers is a z/OS designer, philosopher and evangelist. An IBM Distinguished Engineer, he frequently presents at SHARE and other conferences.