From: Rob Pike <robpike@gmail.com>
To: "John P. Linderman" <jpl.jpl@gmail.com>
Cc: TUHS main list <tuhs@minnie.tuhs.org>
Subject: Re: [TUHS] Remember the ed thread?
Date: Tue, 30 Mar 2021 15:30:56 +1100 [thread overview]
Message-ID: <CAKzdPgytb9RcgxMV0ev-GDjaudDo2ACtrmttMV+e1VuiEJS_CA@mail.gmail.com> (raw)
In-Reply-To: <CAC0cEp9sSvSgh=w3H_qK8W6CS1NApg63+Au7W7UrJpWi=pK=Dw@mail.gmail.com>
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Night operators were known to nap on top of the 1401s. When there was a
need for more paper, they would be gently awakened.
-rob
On Tue, Mar 30, 2021 at 9:30 AM John P. Linderman <jpl.jpl@gmail.com> wrote:
>
>> On Mon, Mar 29, 2021 at 5:16 PM Erik E. Fair <fair-tuhs@netbsd.org>
>> wrote:
>>
>
>
>> Line printers are distinguished not by the width of the paper but by the
>>> printer having enough print heads to print an entire line of output at a
>>> time. That speed advantage made them the preferred output device for
>>> many-page program listings, as opposed to a teleprinter terminals which
>>> were more suitable for interactive computing.
>>>
>> There were originally two styles, the drum printers which DEC sold(e.g.
>> LP20) and the chain printers that IBM offered (e.g. 1401). The drum had
>> all the characters in each of the 132 columns (the upper case only printers
>> were faster because the alphabet was on the drum in two places). The
>> IBM ones has slugs on a rapidly spinning chain that was horizontal (and parallel)
>> to the line being printed. The chain was easily replaceable by the
>> operator - which was one of the duties we would have. When a user queued a
>> printer a set of symbols (*i.e.* the chain of the needed output
>> characters) was specified and the system queued it until the printer had
>> been properly provisioned. For instance, CMU printed checks with a
>> special chain and film ink, so once a night the operator would configure
>> the printer, and tell the queue to print them). Some chains were faster
>> than others, the standard one had N copies of each character.
>>
>> In common to both schemes is that each both styles had 132 hammers and
>> when the proper character was in the position needed, the hammer fired to
>> make an impression the ribbon on the paper, which was caused the noise
>> people associated with computer printers. The high-end IBM 1401 had a
>> hydraulic cover that came down over it and was controlled by the channel
>> processor (it would auto-open when it needed to be serviced - like a new
>> box of paper).
>>
>> This led to the "first commandment of fancy printers": Thou shalt not
> leave thine coffee on top of the printer. -- jpl
>
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next prev parent reply other threads:[~2021-03-30 4:31 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-29 14:34 Larry McVoy
2021-03-29 15:09 ` Anders Damsgaard
2021-03-29 15:26 ` Brantley Coile
2021-03-29 15:36 ` Mark van Atten
2021-03-29 15:43 ` Brantley Coile
2021-03-29 15:52 ` Mark van Atten
2021-03-29 15:45 ` Andy Kosela
2021-03-29 15:51 ` Clem Cole
2021-03-29 17:22 ` arnold
[not found] ` <CALMnNGgWrFRjXk5N4PgTj0_Yw3W5nCR2=CYSASM6dnqTooy8Dw@mail.gmail.com>
2021-03-30 8:53 ` arnold
2021-03-29 15:37 ` Clem Cole
2021-03-29 15:42 ` Anders Damsgaard
2021-03-29 15:49 ` Larry McVoy
2021-03-29 16:01 ` Andy Kosela
2021-03-29 18:12 ` Tom Ivar Helbekkmo via TUHS
2021-03-29 16:20 ` Steve Nickolas
2021-03-29 19:50 ` Rob Pike
2021-03-29 20:50 ` Michael Usher via TUHS
2021-03-29 20:55 ` Larry McVoy
2021-03-29 21:10 ` Erik E. Fair
2021-03-29 21:14 ` Larry McVoy
2021-03-29 21:53 ` Clem Cole
2021-03-29 22:29 ` John P. Linderman
2021-03-30 4:30 ` Rob Pike [this message]
2021-03-30 7:37 ` Harald Arnesen
2021-03-30 15:00 ` Kenneth Goodwin
2021-03-29 15:58 Norman Wilson
2021-03-30 0:11 ` John Cowan
2021-03-29 23:21 M Douglas McIlroy
2021-03-30 3:39 ` Rich Morin
[not found] <CAKH6PiXmR6Jv0bkyOtHuk1ZLV64aeW7bnQkUnzV9-G_JaUVDAA@mail.gmail.com>
2021-03-30 23:38 ` John Cowan
2021-03-31 2:34 ` Bakul Shah
2021-03-31 0:54 Norman Wilson
2021-03-31 1:29 ` John Cowan
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