From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=5.0 tests=DKIM_INVALID,DKIM_SIGNED, HTML_FONT_LOW_CONTRAST,HTML_MESSAGE,MAILING_LIST_MULTI, RCVD_IN_DNSWL_NONE autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 4142 invoked from network); 29 Mar 2021 21:54:09 -0000 Received: from minnie.tuhs.org (45.79.103.53) by inbox.vuxu.org with ESMTPUTF8; 29 Mar 2021 21:54:09 -0000 Received: by minnie.tuhs.org (Postfix, from userid 112) id 59B0F9C886; Tue, 30 Mar 2021 07:54:08 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id EC9129C82B; Tue, 30 Mar 2021 07:53:35 +1000 (AEST) Authentication-Results: minnie.tuhs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=ccc.com header.i=@ccc.com header.b="quXZu4Vm"; dkim-atps=neutral Received: by minnie.tuhs.org (Postfix, from userid 112) id CC3689C82B; Tue, 30 Mar 2021 07:53:31 +1000 (AEST) Received: from mail-qv1-f46.google.com (mail-qv1-f46.google.com [209.85.219.46]) by minnie.tuhs.org (Postfix) with ESMTPS id E95FB9C829 for ; Tue, 30 Mar 2021 07:53:30 +1000 (AEST) Received: by mail-qv1-f46.google.com with SMTP id iu14so1646321qvb.4 for ; Mon, 29 Mar 2021 14:53:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ccc.com; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=Jt5+aG7CDoQpe9Ypbnj5kbjW1o/mF33qWHNldyTEjA4=; b=quXZu4VmzLRRGTJoPHDn7lJcOmfrm+4r8wua8gsBHOWWyPmUF7hmIC/ZCWAO6NOs39 EWLVLi+Tv/Hib7BD6d4xF0mISUhmZ5SUzEx+uoCgK5j+qZnuhHRl2/Htc1AEIdtHUhVI l+wWvv05Yw5XWUnJsrc1Pz4JxpRbjPTZk7gJk= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=Jt5+aG7CDoQpe9Ypbnj5kbjW1o/mF33qWHNldyTEjA4=; b=hhU59dh007+r2DzERBLI8F8mozqUH/9g0H3xtBr7O4ObuvflTyhmP2BB8xHsHMWyHH 2Ww/6zIQ36atD6kWWRxS9iMMUnkWaqSh9l0dj9L/Fnz1m1SzLZDgOv/vwOotcAHFib2q Xxyj6W+DyDbnSFkHwwvUPKZgADkRmtVlFx7ZVV7tRea4P3mqdh5yFbdOIyOqYksrgrYF ZLtvKt27RSNo1nF2mw6Co7cmNuF4l3x0fW/Gq1MgZFOjZfBRNm/KuD/951lM/F79qt6z JJXERMFcE4bmaeDXqGHd91swRq9J3K3qAOwXJNcFIc41teK/HKxwEo9j4pD4oKEJ9KwW 15FQ== X-Gm-Message-State: AOAM530FziXQktZ38qJ8XwUx+jOoxhiXmWEJCynHpU1yXetOJ/06S2lq x9p3q/ebcgxhlLOFA07hx80b43CgFNiVSZJ/RXy9mQ2c67SwezFa X-Google-Smtp-Source: ABdhPJykQogPbO45KHJUf0nmAIMpu7qavbFry5ZTiaS24RmQRqUNsPnmduPYWjtcDOVW+avQgG0eRr6vF0bdUQkVoNk= X-Received: by 2002:ad4:4bce:: with SMTP id l14mr27008689qvw.30.1617054809921; Mon, 29 Mar 2021 14:53:29 -0700 (PDT) MIME-Version: 1.0 References: <4B1F03CA-6387-4FE1-8116-0CB7B5175DE7@ucsc.edu> <20210329205559.GI4209@mcvoy.com> <20718.1617052215@cesium.clock.org> In-Reply-To: <20718.1617052215@cesium.clock.org> From: Clem Cole Date: Mon, 29 Mar 2021 17:53:03 -0400 Message-ID: To: "Erik E. Fair" Content-Type: multipart/alternative; boundary="000000000000872cd605beb3e988" Subject: Re: [TUHS] Remember the ed thread? X-BeenThere: tuhs@minnie.tuhs.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: The Unix Heritage Society mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: TUHS main list Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" --000000000000872cd605beb3e988 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Mon, Mar 29, 2021 at 5:16 PM Erik E. Fair wrote: > Technically, the DEC DECwriter series were dot-matrix printers, not line > printers. They differed from their Teletype predecessors only in print-he= ad > technology, but both printed a single character at a time. Daisywheel > printers were similar. > Right.... > 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 o= nes 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). But even with the cover down it still loud. The original DEC ones were OEM'ed from Centronix and were noted for always being a little random on the hammer timing and thus the print on the paper often looked like the characters bounced on the line. I remember the ones we had on the PDP-10s were awful and the issue with BLISS is that the dot operator is extremely important to your code and the dots were sometimes notoriously missing. Cabling could be difficult too. They were parallel devices and were supposed to have shorter cables (*i.e.* in the machine room). IBM used its own interface, but by the mid-1970s the Centronix printers were pretty standard on the mini-computers and their parallel interface became the standard (in fact the IBM PC supplied a Centronix parallel interface). > > There were dot-matrix line printers of the late 1970s made by Printronix, > which is apparently still around. > IIRC, in 1979 the Printronix cost about $5K, plus another $300-$500 for an Arduino sized parallel to serial converter that they sold so the printer could be remote on a 9600 baud serial line. Until the cheaper lasers came about, these were often the standard printers that UNIX sites had [I was told once that the original Lion's book was printed on one]. They were about =C2=BD the cost of the DEC printers and since it will all pins, did n= ot have the bounce issue the drums had. When the UNIX boxes started to appear at CMU we used them, and IIRC @ UC Berkeley, we had a number of them around Cory Hall also. =E1=90=A7 --000000000000872cd605beb3e988 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable


On Mon, Mar 29, 2021 at 5:16= PM Erik E. Fair <fair-tuhs@netb= sd.org> wrote:
Technically, the DEC DECwriter series were dot-matrix printers, not l= ine printers. They differed from their Teletype predecessors only in print-= head technology, but both printed a single character at a time. Daisywheel = printers were similar.
Rig= ht....=C2=A0


Line printers are distinguished not by the width of the paper but by the pr= inter 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 sui= table for interactive computing.
There were originally two styles, the drum printers which DEC sold(e= .g. LP20)=C2=A0 and the chain printers that IBM offered (e.g. 1401).=C2=A0 = The drum had all the characters in each of the 132 columns (the upper=C2=A0= case only printers were faster=C2=A0b= ecause the alphabet was on the drum in two places).=C2=A0 The IBM ones has slugs on a rapi= dly spinning chain that=C2=A0was horizontal (a= nd parallel) to the line being= = printed.=C2=A0 =C2=A0 The chain was easily replaceable by the operator - wh= ich was one of the duties we would have.=C2=A0 When a user queued a printer= a set of symbols (i.e. the chain of the needed output characters) wa= s specified and the system queued it until the printer had been properly pr= ovisioned.=C2=A0 =C2=A0For instance, CMU printed checks=C2=A0with a special= chain and film ink, so once a night the operator would configure the print= er, and tell the queue to print them).=C2=A0 Some chains were faster than o= thers, 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 p= eople associated with computer printers.=C2=A0 The high-end IBM 1401 had a = hydraulic cover that came down over it and was controlled by the channel pr= ocessor (it would auto-open when it needed to be serviced - like a new box = of paper).=C2=A0 But even with the cover down it still loud.<= /div>

The original DEC ones were OEM'ed from Centronix an= d were noted for always being a little random on the hammer timing and thus= the print on the paper often looked like the characters bounced on the lin= e. I remember the ones we had on the PDP-10s were awful and the issue with = BLISS is that the dot operator is extremely important to your=C2=A0code and= the dots were sometimes notoriously missing.
<= font color=3D"#0000ff">
Cabling could be difficult too.=C2=A0 They were parallel devices and w= ere supposed to have shorter cables (i.e. in the machine room).=C2= =A0 =C2=A0IBM used its own interface, but by the mid-1970s the Centronix=C2= =A0printers were pretty standard on the mini-computers and their parallel i= nterface became the standard (in fact the IBM PC supplied a Centronix=C2=A0= parallel interface).
=C2=A0

There were dot-matrix line printers of the late 1970s made by Printronix, w= hich is apparently still around.
IIRC, in 1979 the Printronix=C2=A0cost about $5K, plus another $300-= $500 for an Arduino sized parallel to serial converter that they=C2=A0sold = so the printer could be remote on a 9600 baud serial line.=C2=A0 =C2=A0Unti= l the cheaper lasers came about, these were often the standard printers tha= t UNIX sites had [I was told once that the original Lion's book was pri= nted on one].=C2=A0=C2=A0 =C2=A0They were about =C2=BD the cost = of the DEC printers and since it will all pins, did not have the bounce iss= ue the drums had. =C2=A0 =C2=A0When the UNIX boxes started to appear at CMU= we used them, and IIRC @ UC Berkeley, we had a number of them around Cory = Hall also.=C2=A0
3D""=E1=90=A7
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