Received: by 10.66.86.6 with SMTP id l6mr3269856paz.11.1353353293182;
        Mon, 19 Nov 2012 11:28:13 -0800 (PST)
Path: 6ni95580pbd.1!nntp.google.com!news.glorb.com!eternal-september.org!feeder.eternal-september.org!mx04.eternal-september.org!.POSTED!not-for-mail
From: Dan Espen <des...@verizon.net>
Newsgroups: alt.folklore.computers
Subject: Re: 360/20, was 1132 printer history
Date: Mon, 19 Nov 2012 14:28:12 -0500
Organization: A noiseless patient Spider
Lines: 40
Message-ID: <ic4nkl75pv.fsf@home.home>
References: <5023b169$17$fuzhry+tra$mr2ice@news.patriot.net>
	<k0bcr1$u4e$2@dont-email.me> <k0bm7c$2n9r$1@leila.iecc.com>
	<502a573a$61$fuzhry+tra$mr2ice@news.patriot.net>
	<k0e2oh$11bi$1@leila.iecc.com> <k7rvqu$ged$1@dont-email.me>
	<mddwqxpknbm.fsf@panix5.panix.com> <k80d97$2as$1@dont-email.me>
	<k81kme09au@news6.newsguy.com>
	<c3042dd5-c3c5-4cf9-9824-6359ea03caf8@r6g2000yqd.googlegroups.com>
	<k842um0236c@news3.newsguy.com>
	<d428ebed-5aef-4d08-96e2-071c93a4c5d6@3g2000yqn.googlegroups.com>
	<mdd6252ig6b.fsf@panix5.panix.com> <k8dc9p$evk$1@dont-email.me>
	<5fb0b516-0a23-48b3-aad7-2a4bcc45bd85@h15g2000yqe.googlegroups.com>
	<ic8v9x7dzh.fsf@home.home>
	<915ca312-be5f-4749-aa41-ac67e5a9db59@g8g2000yqp.googlegroups.com>
Mime-Version: 1.0
Injection-Info: mx04.eternal-september.org; posting-host="960b39603e44c0554faedf0065e3beaf";
	logging-data="27814"; mail-complaints-to="ab...@eternal-september.org";	posting-account="U2FsdGVkX1/MaAFrLO14WN1BWzVQONkqmoIyImzbcCY="
User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.3 (gnu/linux)
Cancel-Lock: sha1:1dlc9bEOVIXqW/0ZMLlv/QcDmWw=
	sha1:aS8ofBbhkMxcowKZLd6WH960qTg=
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 8bit

hanco...@bbs.cpcn.com writes:

> On Nov 19, 11:29 am, Dan Espen <des...@verizon.net> wrote:
>
>> Hmm, there never was a follow on to the 360/20.
>> It was programmed in RPG.
>> I wonder what IBM was thinking when they decided to create a new
>> architecture instead of build another small 360-like machine.
>
> The issue was cost and attracting low-volume customers.
>
> Per the IBM history (System/360)--the System/3 was originally
> conceived as a low cost punched card computer.  They saved money on
> the S/360-20 by using serial card readers (instead of more costly
> parallel readers*) and punch and an abbreviated instruction set (37 in
> the model 20 vs. 143 in S/360).  But the S/360-20 still wasn't cheap
> enough for the lowest users.
>
> System/3 reduced costs further by using a miniature punched card and
> other smaller units.  It had only 28 instructions.
>
> The S/3 "constituted a candid concession that S/360 could not bridge
> thw widening opportunities in the marketplace, at least not with the
> technologies available at the time."
>
> The S/360-20 basic machine rented for $2,000/month.  The S/3-model 10
> basic model rented for $1,000/month.
>
> *Tab machines used parallel reading, which fit their functionality.
> But that was more expensive to accomodate in a computer which used a
> character format.  Going to serial card readers and punches saved
> machinery and electronics at the cost of speed.

A serial reader could have been put on the 360/20.
So, 37 instructions vs. 28 justified a whole new architecture?

A bit strange.

-- 
Dan Espen