4 ms·

> Hollerith punch cards Ever wonder why a "standard terminal screen" size defaults to 80 columns? Because of punch cards - a standard punch card has 80 column

by cr0sh 9y ago

> Hollerith punch cards Ever wonder why a "standard terminal screen" size defaults to 80 columns? Because of punch cards - a standard punch card has 80 columns (rows vary, but a standard was 10-12 rows), and IBM made this standard on the PC for display to be able to show a punch card data on the screen. Likely this comes from dumb serial terminals of the era...so the standard carried over, for backwards compatibility.

gumby 9y ago
> Because of punch cards - a standard punch card has 80 columns (rows vary, but a standard was 10-12 rows), and IBM made this standard on the PC for display to be able to show a punch card data on the screen. > Likely this comes from dumb serial terminals of the era...so the standard carried over, for backwards compatibility. Hey, I am from the serial dumb terminal era, which really only goes back to the 1960s! But you're right, that's where the 80 columns came from, and even as the tech got better, all that happened is we got more rows (24 was quite common, then to be exotic 48). I was already using bit mapped displays and mice in the late 70s when the 48 row terminals showed up (I had one in my office in school; I didn't rate a lispm terminal. Had to go to work for that). I wrote a lot of code on Ann Arbor Ambassador 80x48 terminals. I don't know where the 132 column printer "standard" came from. That's the stuff that printed on the green and white paper (first chain printers -- wow!) then dot matrix and finally daisy wheel. Not sure if there were golf ball printers that weren't typewriters but I was never an IBM user. I never saw a 132 column terminal -- it's possibly you could get a VT100 into that mode, I'm not sure. Remember, the character generation etc was often hard wired! I still use my terminals in 80 or 132 character mode. Actually, since they are "soft" I use them in 81 & 133 character mode to avoid spurious wrapping.
- kens 9y ago
  > I don't know where the 132 column printer "standard" came from. Back in 1959, the IBM 1401's printer (the 1403) is what made 132 columns standard. But I haven't been able to figure out why they went with 132 columns. I discussed this with the 1401 team at the Computer History Museum and nobody came up with a good explanation. There's no solid technical or business reason for 132 columns.
  - gshubert17 9y ago
    Perhaps 11 inches wide times 12 columns per inch?
    - diggernet 9y ago
      Interesting thought. According to wiki, the printer used 10cpi though. Which suggests 132 columns plus margins on 14" paper. But that still doesn't answer why 132 and not 130 or 136 or whatever. Other variants of the printer had 100 columns (11" paper?) or 120 columns (what size paper?). Edit: Looking for more details on paper sizes for the 1403 printer, I find that the 132 column model was capable of simultaneously printing up to eight 1.5" adding machine tapes (13 chars per tape), or up to four 3.1" adding machine tapes (29 chars per tape), with a few columns lost due to margins and spacing between the tapes. Perhaps that was a factor in determining the 132 value?
      - gumby 9y ago
        > I find that the 132 column model was capable of simultaneously printing up to eight 1.5" adding machine tapes... WEIRD! What's the use case for printing large numbers of adding machine tapes in parallel? I don't believe there were electronic cash registers in that period so I can't imagine it would be for auditing receipt tapes (and anyway, would you use, you know, the computer for that?).
        diggernet 9y ago
        Yeah, kind of puzzled about that myself. But see for yourself, on page 41: http://bitsavers.trailing-edge.com/pdf/ibm/1403/GA24-3073-8_1403_printer.pdf http://bitsavers.trailing-edge.com/pdf/ibm/1403/GA24-3073-8_...
- flyinghamster 9y ago
  > I never saw a 132 column terminal -- it's possibly you could get a VT100 into that mode, I'm not sure. If you had the Advanced Video Option installed, there was definitely a 132-column mode available via \033[?3h (with \033[?3l to return to 80-column). The (very few) VT100s that my high school had were so equipped. The VT102 came with the Advanced Video Option preinstalled.

by cr0sh 9y ago

gumby 9y ago

> Because of punch cards - a standard punch card has 80 columns (rows vary, but a standard was 10-12 rows), and IBM made this standard on the PC for display to be able to show a punch card data on the screen. > Likely this comes from dumb serial terminals of the era...so the standard carried over, for backwards compatibility. Hey, I am from the serial dumb terminal era, which really only goes back to the 1960s! But you're right, that's where the 80 columns came from, and even as the tech got better, all that happened is we got more rows (24 was quite common, then to be exotic 48). I was already using bit mapped displays and mice in the late 70s when the 48 row terminals showed up (I had one in my office in school; I didn't rate a lispm terminal. Had to go to work for that). I wrote a lot of code on Ann Arbor Ambassador 80x48 terminals. I don't know where the 132 column printer "standard" came from. That's the stuff that printed on the green and white paper (first chain printers -- wow!) then dot matrix and finally daisy wheel. Not sure if there were golf ball printers that weren't typewriters but I was never an IBM user. I never saw a 132 column terminal -- it's possibly you could get a VT100 into that mode, I'm not sure. Remember, the character generation etc was often hard wired! I still use my terminals in 80 or 132 character mode. Actually, since they are "soft" I use them in 81 & 133 character mode to avoid spurious wrapping.

kens 9y ago
> I don't know where the 132 column printer "standard" came from. Back in 1959, the IBM 1401's printer (the 1403) is what made 132 columns standard. But I haven't been able to figure out why they went with 132 columns. I discussed this with the 1401 team at the Computer History Museum and nobody came up with a good explanation. There's no solid technical or business reason for 132 columns.
- gshubert17 9y ago
  Perhaps 11 inches wide times 12 columns per inch?
  - diggernet 9y ago
    Interesting thought. According to wiki, the printer used 10cpi though. Which suggests 132 columns plus margins on 14" paper. But that still doesn't answer why 132 and not 130 or 136 or whatever. Other variants of the printer had 100 columns (11" paper?) or 120 columns (what size paper?). Edit: Looking for more details on paper sizes for the 1403 printer, I find that the 132 column model was capable of simultaneously printing up to eight 1.5" adding machine tapes (13 chars per tape), or up to four 3.1" adding machine tapes (29 chars per tape), with a few columns lost due to margins and spacing between the tapes. Perhaps that was a factor in determining the 132 value?
    - gumby 9y ago
      > I find that the 132 column model was capable of simultaneously printing up to eight 1.5" adding machine tapes... WEIRD! What's the use case for printing large numbers of adding machine tapes in parallel? I don't believe there were electronic cash registers in that period so I can't imagine it would be for auditing receipt tapes (and anyway, would you use, you know, the computer for that?).
      - diggernet 9y ago
        Yeah, kind of puzzled about that myself. But see for yourself, on page 41: http://bitsavers.trailing-edge.com/pdf/ibm/1403/GA24-3073-8_1403_printer.pdf http://bitsavers.trailing-edge.com/pdf/ibm/1403/GA24-3073-8_...
flyinghamster 9y ago
> I never saw a 132 column terminal -- it's possibly you could get a VT100 into that mode, I'm not sure. If you had the Advanced Video Option installed, there was definitely a 132-column mode available via \033[?3h (with \033[?3l to return to 80-column). The (very few) VT100s that my high school had were so equipped. The VT102 came with the Advanced Video Option preinstalled.