Interesting. I still set my shell windows to 132 chars wide, but I do that because I used VT100 terminals way back.
Accounting machines, the IBM 1403, and why printers standardized on 132 columns
21–30 of 31 posts
Re: Accounting machines, the IBM 1403, and why printers standardized on 132 columns
#22Those of us that were around in the days of mainframes and line printers remember that actually you sent 133 columns of characters to the printer, column 0 being the "carriage control" character. The most popular being blank, to advance one line, '1', to do a page eject a.k.a. top-of-form, and '+', overprint. The story that I heard is that the '+' character's over-strike behavior was a side-effect of logic minimizati…
IDK. The wikipedia article on the 1403 does not mention any 1403A, just 1403N and 1 through 7. I doubt the overprinting was an accident, 'PUT SKIP (0);' worked for all the versions of PL/1 I used from 1970 through around 1990. Didn't even IBM use it for drawing maps and graphs on the 1403? I remember that the standard was to fill a region with O's to get a lightly shaded region, next darker was O overstruck with X, t…
I've heard the breaking chain story many times, but I suspect it's mostly an urban legend. At least on the 1403, the hammers can't all fire at once. The chain and hammers have different spacings so only one hammer is lined up at a time, 11.1μs apart; the worst you could do is fire every third hammer in rapid sequence. For reference, a standard chain sequence is
1234567890#@/STUVWXYZ‡,%JKLMNOPQR-$*ABCDEFGHI+.¤
The 1403's print chain is pretty complicated to understand, so I built an animation: http://righto.com/ibm1401/printchain.html
Re: Accounting machines, the IBM 1403, and why printers standardized on 132 columns
#23Those of us that were around in the days of mainframes and line printers remember that actually you sent 133 columns of characters to the printer, column 0 being the "carriage control" character. The most popular being blank, to advance one line, '1', to do a page eject a.k.a. top-of-form, and '+', overprint. The story that I heard is that the '+' character's over-strike behavior was a side-effect of logic minimizati…
The more things change, the more they stay the same. They installed a "pay us more money" switch. In hardware. The lingering scent of the unmitigated gall is still overpowering even years later.
It wasn't unique to them. In the early 80's I worked at an OEM minicomputer company that now would be called a startup. (I don't recall the term existing then.) We built systems from DEC 8-bit processors and Control Data disk drives. The drives were 40MB, 80MB, and (I think; it's been a while) 150MB. We sold an entry-level system with a 20MB drive. It was a 40MB drive with a hardware switch to disable addressing half the platters. When the customers would pony up the proportionately significant fee for a "upgrade", the hardware guy would go in, make a show of disassembling and polishing things, and when no one was looking, flip the switch to enable addressing the entire drive.
Re: Accounting machines, the IBM 1403, and why printers standardized on 132 columns
#24Those of us that were around in the days of mainframes and line printers remember that actually you sent 133 columns of characters to the printer, column 0 being the "carriage control" character. The most popular being blank, to advance one line, '1', to do a page eject a.k.a. top-of-form, and '+', overprint. The story that I heard is that the '+' character's over-strike behavior was a side-effect of logic minimizati…
It was a bit different with the IBM 1403 printer on the IBM 1401 computer. You added a suffix to the write line instruction to suppress the line feed. This optional "space suppression" feature cost $63. As far as I can tell, using a '+' in the first column to overprint was a Fortran thing, known as Fortran Carriage Control. One entertaining feature of the 1403 was that form feeds were controlled by a 12-column paper…
How did the 1403 start & stop the paper advance? Once the paper gets moving, there's a lot of inertia there. Was there an air bladder in the hydraulic line to absorb fluid-hammer from the rapid pressure changes?
One of the printers I worked on in the USAF had electromagnetic clutches - one would engage to hold the paper in place while the other would open to disengage the drive belt. To move the paper, the "hold" clutch would disengage and the "drive" clutch would engage for just long enough to move it the required distance. And then the clutch action would reverse (hold clutch engage, drive clutch release) to stop the paper's motion.
After a while, the clutch material would wear out and you would get the infinite form-feed.
Edit: For the curious, this was taken at the school at Sheppard AFB in 1983: https://imgur.com/a/J74K6wM
Re: Accounting machines, the IBM 1403, and why printers standardized on 132 columns
#25Earlier quoted context omitted.
IDK. The wikipedia article on the 1403 does not mention any 1403A, just 1403N and 1 through 7. I doubt the overprinting was an accident, 'PUT SKIP (0);' worked for all the versions of PL/1 I used from 1970 through around 1990. Didn't even IBM use it for drawing maps and graphs on the 1403? I remember that the standard was to fill a region with O's to get a lightly shaded region, next darker was O overstruck with X, t…
I've heard the breaking chain story many times, but I suspect it's mostly an urban legend. At least on the 1403, the hammers can't all fire at once. The chain and hammers have different spacings so only one hammer is lined up at a time, 11.1μs apart; the worst you could do is fire every third hammer in rapid sequence. For reference, a standard chain sequence is 1234567890#@/STUVWXYZ‡,%JKLMNOPQR-$*ABCDEFGHI+.¤ The 140…
I used to work at IBM as a CSR (maybe we were CEs back then?) fixing 1403s and other mainframe boxes.
Man it would have been so useful to have your fantastic animation back then. I came on the scene too late to ever get any formal training on 1403, so I ended up learning most of it the hard way. I don't think I ever fully understood the hammer mechanics as you have explained it.
An animation is truely worth 1000 words.
Re: Accounting machines, the IBM 1403, and why printers standardized on 132 columns
#26Read the notes, it's especially interesting: > in 1954, Remington Rand introduced the first high-speed drum printer, the "High Speed Off Line Printer System" for the UNIVAC computer. This printer produced 600 lines per minute at 130 characters per line. The printer used 18 kW of power and was cooled by 8 gallons per minute of chilled water. Wow.
A friend was a programmer in the 90's for a firm that was getting a new higher-end IBM 3090. He was in the manager's office looking over the layout for the installation, when he asked "Where is the water pump going?"
Blank look, followed by the "oh shit" look.
Re: Accounting machines, the IBM 1403, and why printers standardized on 132 columns
#27Earlier quoted context omitted.
It was a bit different with the IBM 1403 printer on the IBM 1401 computer. You added a suffix to the write line instruction to suppress the line feed. This optional "space suppression" feature cost $63. As far as I can tell, using a '+' in the first column to overprint was a Fortran thing, known as Fortran Carriage Control. One entertaining feature of the 1403 was that form feeds were controlled by a 12-column paper…
How did the 1403 start & stop the paper advance? Once the paper gets moving, there's a lot of inertia there. Was there an air bladder in the hydraulic line to absorb fluid-hammer from the rapid pressure changes? One of the printers I worked on in the USAF had electromagnetic clutches - one would engage to hold the paper in place while the other would open to disengage the drive belt. To move the paper, the "hold" clu…
The 1403 has electrically-controlled valves to send fluid from the constantly-running pumps to the hydraulic motor to do a space (line feed) or skip (form feed). There's a back pressure bypass valve that relieves the pressure when the printer advance stops.
The 1403 Field Engineering manual goes into great detail on the hydraulic system, starting at page 56. The momentum when stopping is described on page 62. Link: http://ibm-1401.info/0KenShirriff/IBM_Field_Engineering_Manu...
Re: Accounting machines, the IBM 1403, and why printers standardized on 132 columns
#28Earlier quoted context omitted.
The more things change, the more they stay the same. They installed a "pay us more money" switch. In hardware. The lingering scent of the unmitigated gall is still overpowering even years later.
It wasn't unique to them. In the early 80's I worked at an OEM minicomputer company that now would be called a startup. (I don't recall the term existing then.) We built systems from DEC 8-bit processors and Control Data disk drives. The drives were 40MB, 80MB, and (I think; it's been a while) 150MB. We sold an entry-level system with a 20MB drive. It was a 40MB drive with a hardware switch to disable addressing half…
I heard of a Control Data mainframe that could be "upgraded" by cutting a single wire.
Re: Accounting machines, the IBM 1403, and why printers standardized on 132 columns
#29Interesting. I still set my shell windows to 132 chars wide, but I do that because I used VT100 terminals way back.
And why do you think VT100's had that capability?
Re: Accounting machines, the IBM 1403, and why printers standardized on 132 columns
#30> the IBM 705 business computer rented for $43,000 a month (almost $400,000 in current dollars). But the IBM 1401 could be rented for $2500 per month, opening up the market to medium-sized businesses Amazing that we are basically back in that place again: renting computers or paying for computer time.
We are due for a back-lash soon. "On-premise cloud" or something.
Doubtful. The cost driver has ceased to be the machine itself and has become all the ancillaries, system admins and internet trunks and data center redundancy and...