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Comment by aetherson

5 years ago

When I was a CS major in the 90's, one of my professors told me a story of his own college days, with punch-card computers.

His university bought a tape reader (like, punched paper tape, not magnetic tape) to do the boot code of the computer, on the theory that tape was a little easier to manage than punch-cards for the boot (you can't lose one of the cards, or get them out of order, etc with tape). So my prof and some of his friends start playing with the tape reader, and they realize that what controls the IO speed of the tape is actually the tensile strength of the tape -- if the feeder tries to put too much force on it, it will tear the paper tape. The actual computer can read the instructions much faster than the tape can physically handle.

So they got some plastic tape instead, and punched the boot code in the (much stronger) plastic tape. Then, to boot the computer, they'd feed the plastic tape through the part of the reader that actually read, bypassing the mechanical part that pulled and wound the tape, and then manually grab the other end and yank on it as hard as they could, basically starting the computer like it was one of those old lawnmowers that you pulled the cord to turn over the engine.

I love this kind of stuff. The fact that we (people in our field; not me specifically) had to and could do stuff like this must seem crazy ancient to the younger folks here. I did boot my first computer from a cassette tape, and I can still remember what it sounded like and it's so, so very nostalgic. And many of us did get our first internet access via these crazy noises as well. I'm sure I could also listen to a modem connecting and tell you what speed it had negotiated from 1200baud all the way up to 56k, since each new sound was, at one point, the pinnacle of excitement since I'd just upgraded to something new (and then I heard it thousands of times).

  • You will enjoy this classic. It's a lovely image showing the dialup handshake . My first modem was a Hayes 1200 baud. Every modem after seemed to double. The protocols got better too. Bidirectional transfers, wow.

    http://www.windytan.com/2012/11/the-sound-of-dialup-pictured...

    • My first modem was a Hayes-brand 300 baud modem. Atari 800 computer.

      So I'll kindly ask you to get off my lawn, whipper-snapper.

      (BTW I listen to a lot of ambient / noise / drone music, and a while ago, some artist took those modem sounds, slowed them down, put in some reverb, etc. and it was downright ghostly).

      It wasn't exactly this: https://www.youtube.com/watch?v=IF2v32xCD0Y

      but it wasn't too far off.

      4 replies →

  • Same here. I loaded programs from cassette tape into a Soviet clone of a Sinclair computer. Each program started with some sort of a loader block that produced a constant pitch. I would use a screwdriver to adjust the magnetic read head of the cassette player and listen for the pitch to be just right during the loader block in order to get the actual program to load correctly. Good memories.

  • When I was in college, it was accepted fact that 300 baud was the physical limit over POTS. Eventually, we got to 56k :-)

    • When I first saw an ad for a "soon to be released" 9600 bps modem, I excitedly mentioned it on a local BBS, where all of the older wiser users told me it was impossible and the ad must have been a joke. 1200 baud was still relatively new at the time and error prone even with a parity bit so I could understand some of their skepticism. The central offices were still in the process of being converted over to digital and lines were still noisy at times. As the quality of the local loop improved, so did modem speeds.

    • Well never can afford one then. Did saw many a couple of years which use this to win 7! It finally come at end as the patch of win 10 s too large to bear. But nice to see some 56k us robotics after so many decades.

  • I always hated that damn modem screeching sound. I once popped off the speaker on the modem itself, because it was so annoying.

    And then I recall, there was always a commercial playing on the radio, that had that sound. Maybe it was for the now dead U.S. Robotics. I can’t recall.

    I was glad to finally get cable modem.

  • I could tell what speed my first modem connected at because my DEC modem had a physical switch to select between 300 and 1200 baud. It also had a physical switch between line and data: no acoustic coupler required for this baby.

Back in the late eighties I was in the Air Force and we had a Burroughs machine; replete with all the lights you see in old science fiction; that could be booted through paper tape. I was an octal setup. We also could theoretically boot this machine by switches but never saw that done.

This was one of the first machines built for the service that did not require tubes so that gives you the idea of the age of this and it was in daily use in the 1986-1989. Even the main base computer, Sperry 1100/60? took cards in for data input. Late 88,89 we finally got most cards down to disk images uploaded through a Sperry branded PC. My first useful Turbo Pascal program replaced the provided software and could read/write from the mainframe at many times the rate of the canned software.

We also jokingly had a kick start Sperry, one pack would stick sometimes on boot; you had to swap packs for secure processing; and the fix was to face away from it and hit the side firmly with your foot flat on.

Great story! FWIW this is kind of the origin story for Mylar "paper tape" as well. When paper tape started being used for controlling machine tools (the NC in CNC), the paper tape would not hold up well in a shop. It could get grease or water on it which would compromise its integrity and then it would tear. So a "stronger" paper tape was created but it had to be compatible with older paper tape reader/punches. It was great stuff.

Part of me wants to think that that would add wear to the mechanism but the other part of me remembers how things were built back then.

Great post, it made me smile and brought some memories. Btw I did use punch tapes in the beginning of times and the speed with which the mech pulled those through was insanely fast (at least to my eye). Maybe I've dealt with some later generation tech?

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