
Accounting machines, the IBM 1403, and why printers standardized on 132 columns - mmastrac
http://www.righto.com/2019/01/accounting-machines-ibm-1403-and-why.html
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dbcurtis
Those 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 minimization in the printer controller of the 1403, and
became very popular after someone discovered it.

IBM then issued an FCO (Field Change Order) that customer engineers installed
in all 1403 printers that were on maintenance contracts, which was all of
them, because you could not survive without a maintenance contract. The FCO
"corrected the logic bug" that allowed overprinting. However, the newly
announced 1403A printer supported overprinting as a feature.

The FCO included a toggle switch that allowed the customer engineer to do an
instant field upgrade to the 1403A. Assuming, of course, that you paid for the
field upgrade and increased rental and maintenance fees of the 1403A.

(I heard this story from an office mate who had been around in those days. He
was a systems programmer that got the job by the then-standard path. As an
undergrad, he figured out how to hack the OS to get free computer time. When
they caught him, they offered him a job as an assistant systems programmer on
the condition that he not share the secret.)

~~~
kens
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 tape. By punching holes in the tape, you could quickly form
feed to 12 different positions on your page. (This was useful for pre-printed
forms.) The only problem was if you did a form feed and there wasn't a hole in
that column in the paper tape, the printer would feed at high speed through
the entire box of paper without stopping. (The 1403 used a hydraulic motor for
high-speed form feeds. If you see hydraulic fluid under the printer at the
Computer History Museum, that's why.)

~~~
chiph
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](https://imgur.com/a/J74K6wM)

~~~
kens
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...](http://ibm-1401.info/0KenShirriff/IBM_Field_Engineering_Manual_of_Instruction_1403_Printers_225_6492_3.pdf)

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gumby
This is a lovely well-researched article on the origin of a number of
otherwise bizarre I/O constants.

E.g. the following: "...why not use 130 instead of 132? Due to the complex
alignment between the 1403's chain and the print hammers, a line width
divisible by 3 (such as 132) works out better."

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etbusch
An interesting read as always from Ken.

I've got a first-generation Apple Dot Matrix Printer that's up next for a
restoration. I understand that I can still get drivers for this, but does
anyone know what it might be worth? eBay comes up with nothing.

~~~
bitwize
Dude, you send your friends greeting cards or invitations run off in Print
Shop, that thing will be worth its weight in gold!

EDIT: Apparently this printer is the predecessor to the ImageWriter.

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Animats
Why the IBM 402 had 43 alphanumeric typebars:

    
    
        INTERNATIONAL BUSINESS MACHINES CORPORATION
        0000000001111111111222222222233333333334444
        1234567890123456789012345678901234567890123

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kens
Is that real or an urban legend or somewhere in between?

Slightly tangentially, IBM often went by "International" back then. Products
would have an "International" logo on them, and names like "International
Automatic Carriage". e.g.:
[https://archive.computerhistory.org/resources/access/text/20...](https://archive.computerhistory.org/resources/access/text/2009/09/102652895.05.24.acc.pdf)

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acqq
Read 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.

~~~
chiph
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.

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hsnewman
I was in college learning Fortran on one of these. Half way through the class
they moved us to a mainframe, I was amazed at how much more the compiler
reported on the mainframe vs the 1403 (errors and warnings).

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miohtama
50 years later we still cannot develop programming text editors with soft line
wrap to satisfy everyone.

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gumby
> 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.

~~~
jacobush
We are due for a back-lash soon. "On-premise cloud" or something.

~~~
mark-r
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...

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mark-r
My first exposure to line printers was through a Control Data mainframe at a
University in the mid '70's. There were a few Control Data printers at
centralized locations, and user operated Univac printers more scattered. Both
used 14 7/8 paper with 132 columns.

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dboreham
Interesting. I still set my shell windows to 132 chars wide, but I do that
because I used VT100 terminals way back.

~~~
mark-r
And why do you think VT100's had that capability?

