4 ms·

Deja vu! I spent years fixing mainframes at IBM and the 1403 lived on for years after the 1401, attached to more modern systems like System/360. It was quite a

by abraae 9y ago

Deja vu! I spent years fixing mainframes at IBM and the 1403 lived on for years after the 1401, attached to more modern systems like System/360. It was quite a beast to maintain. The main part is a "train" of metal slugs with the letters, digits and a few symbols that hurtle around on a steel oiled track. To print a letter H, the machine fires an electromagnet that drives a hammer onto the next H as it flies past. One of the maintenance activities was adjusting the hammer strike, which you did by printing a page full of H's, and moving the strike forwards and backwards so that the left and right uprights of the "H" were both printed clearly. The worst scenario with this machine was a "train crash", when one of the slugs dug into the train and all of the flying metal slugs smashed into each other in a giant screaming hail of destruction. Other activities: - topping up the hydraulic fluid - replacing dead hammer drivers

netsharc 9y ago
Hah, I never thought I would ever hear a story about a computer that needs its hydraulic fluids topped-up. My first modem is 28.8k, I guess you can call me young'un...
- jbuzbee 9y ago
  I suspect there are a few of us on here that started out with a 300 baud acoustic coupler modem...
  - dmd 9y ago
    110 baud, here.
    - wpietri 9y ago
      Ah yes! Bit rates so low you could try to whistle them.
- abraae 9y ago
  Young'un indeed! IBM used to use hydraulics pretty extensively. Their 2311 disk drives used hydraulic actuators to move the heads in and out over the platters. Hot pressurized oil and spinning magnetic media - a combination not made in heaven. I seem to remember stories about injuries caused by hydraulic oil piercing engineer body parts. Thankfully they were phasing out as I started. Though living in the colonies, we used to see machines still working that were probably nowhere to be found in the US any more.
  - King-Aaron 9y ago
    > I seem to remember stories about injuries caused by hydraulic oil piercing engineer body parts. Hydraulic fluid injection injuries are appalling, and can often require amputation. I recall assisting a guy who had split a main line on a bobcat, and had oil spray into his hand. He lost most of his fingers.
- leggomylibro 9y ago
  Funny, 'cause I see a few on the way to work every day. I mean...I assume...backhoes and things need to have their fluid topped up, right?
teddyh 9y ago
From: (http://wiretap.area.com/Gopher/Library/Techdoc/Lore/rumor.net http://wiretap.area.com/Gopher/Library/Techdoc/Lore/rumor.ne...): From: hinojosa@hp-sdd.hp.com (Daniel Hinojosa) Subject: Printer chain problems Date: 6 Feb 89 A friend of mine told a story of one of these printers he and another friend destroyed in a most interesting manner. These printers had, it would seem, a sort of chain that held all of the characters. I guess they held about three complete sets of the alphabet plus special characters. These chaps read the chain and created a file in their system that had all of the characters of one pass in it. They gave the command to print the file. Upon doing so the printer starts to spin the chain, then SMACK! Trying to print all of those characters at once while the chain was moving, didn't quite work. The fellow said they found the print characters in various parts of their office for years thereafter. From: johnl@ima.ima.isc.com (John R. Levine) Subject: Printing a line Date: 8 Feb 89 ...The letters on the print chain are all scrambled up. Each time the chain moves, some fraction of the letters on the chain will be in front of the place where those particular letters are supposed to print, so the printer fires just those hammers. Then the chain moves, some more hammers fire, etc. The particular hack that Mr. Hinojosa and I described reprogrammed the printer so it would think that every letter on the line was correctly placed and so fire all the hammers at once. That makes quite a lot of noise (normally, only 10 or so of the 120 or 132 hammers go off at once) and moreover turned out to use more power than the printer was prepared to supply thus blowing the fuse and causing other problems. From: darin@nova.laic.uucp (Darin Johnson) Subject: Problematic printouts Date: 9 Feb 89 Actually, the print chains are not in alphabetical order. They are magically ordered by some arcane formula. Some of the printers are designed so that the hammer will strike the character just as the correct character is at the correct place in the line (the chain rotates at very fast speeds). Often, many characters will get printed at the same time, and no more than 2 rotations of the chain are ever needed to print a line (which is why they are fast). Presumably, the right set of characters on a line will cause all the hammers (132) to strike at the same time (while the chain is rotating). I had related a story like this to a friend in college and (unknown to me) had decided to try it. He spent a night carefully going over the chain and determining the proper sequence to send. The next evening, he decided to print his file, and had me watch (only one line was printed). The job printed and we ran downstairs. The printer was still rocking slightly. Opening up the cover, the chain was still intact, but had come completely off the drive that held it. We tore out the offending sheet of paper with the incriminating line (smudged and garbled) and complained to the operator on duty that the printer was broken again. I don't think my friend ever tried it again.

by abraae 9y ago

netsharc 9y ago

Hah, I never thought I would ever hear a story about a computer that needs its hydraulic fluids topped-up. My first modem is 28.8k, I guess you can call me young'un...

jbuzbee 9y ago
I suspect there are a few of us on here that started out with a 300 baud acoustic coupler modem...
- dmd 9y ago
  110 baud, here.
  - wpietri 9y ago
    Ah yes! Bit rates so low you could try to whistle them.
abraae 9y ago
Young'un indeed! IBM used to use hydraulics pretty extensively. Their 2311 disk drives used hydraulic actuators to move the heads in and out over the platters. Hot pressurized oil and spinning magnetic media - a combination not made in heaven. I seem to remember stories about injuries caused by hydraulic oil piercing engineer body parts. Thankfully they were phasing out as I started. Though living in the colonies, we used to see machines still working that were probably nowhere to be found in the US any more.
- King-Aaron 9y ago
  > I seem to remember stories about injuries caused by hydraulic oil piercing engineer body parts. Hydraulic fluid injection injuries are appalling, and can often require amputation. I recall assisting a guy who had split a main line on a bobcat, and had oil spray into his hand. He lost most of his fingers.
leggomylibro 9y ago
Funny, 'cause I see a few on the way to work every day. I mean...I assume...backhoes and things need to have their fluid topped up, right?

teddyh 9y ago

From: (http://wiretap.area.com/Gopher/Library/Techdoc/Lore/rumor.net http://wiretap.area.com/Gopher/Library/Techdoc/Lore/rumor.ne...): From: hinojosa@hp-sdd.hp.com (Daniel Hinojosa) Subject: Printer chain problems Date: 6 Feb 89 A friend of mine told a story of one of these printers he and another friend destroyed in a most interesting manner. These printers had, it would seem, a sort of chain that held all of the characters. I guess they held about three complete sets of the alphabet plus special characters. These chaps read the chain and created a file in their system that had all of the characters of one pass in it. They gave the command to print the file. Upon doing so the printer starts to spin the chain, then SMACK! Trying to print all of those characters at once while the chain was moving, didn't quite work. The fellow said they found the print characters in various parts of their office for years thereafter. From: johnl@ima.ima.isc.com (John R. Levine) Subject: Printing a line Date: 8 Feb 89 ...The letters on the print chain are all scrambled up. Each time the chain moves, some fraction of the letters on the chain will be in front of the place where those particular letters are supposed to print, so the printer fires just those hammers. Then the chain moves, some more hammers fire, etc. The particular hack that Mr. Hinojosa and I described reprogrammed the printer so it would think that every letter on the line was correctly placed and so fire all the hammers at once. That makes quite a lot of noise (normally, only 10 or so of the 120 or 132 hammers go off at once) and moreover turned out to use more power than the printer was prepared to supply thus blowing the fuse and causing other problems. From: darin@nova.laic.uucp (Darin Johnson) Subject: Problematic printouts Date: 9 Feb 89 Actually, the print chains are not in alphabetical order. They are magically ordered by some arcane formula. Some of the printers are designed so that the hammer will strike the character just as the correct character is at the correct place in the line (the chain rotates at very fast speeds). Often, many characters will get printed at the same time, and no more than 2 rotations of the chain are ever needed to print a line (which is why they are fast). Presumably, the right set of characters on a line will cause all the hammers (132) to strike at the same time (while the chain is rotating). I had related a story like this to a friend in college and (unknown to me) had decided to try it. He spent a night carefully going over the chain and determining the proper sequence to send. The next evening, he decided to print his file, and had me watch (only one line was printed). The job printed and we ran downstairs. The printer was still rocking slightly. Opening up the cover, the chain was still intact, but had come completely off the drive that held it. We tore out the offending sheet of paper with the incriminating line (smudged and garbled) and complained to the operator on duty that the printer was broken again. I don't think my friend ever tried it again.