Mechanical calculators (was: Re: *updating* 8088's)
M H Stein
dm561 at torfree.net
Mon Dec 3 00:46:01 CST 2007
Date: Sun, 02 Dec 2007 19:18:11 +0100
From: "Arno Kletzander" <Arno_1983 at gmx.de>
Subject: Mechanical calculators (was: Re: *updating* 8088's)
M H Stein <dm561 at torfree.net> wrote:
>> The IBM unit record or Tabulating machines that we've been discussing
>> had their roots in the same principles as these calculators, adding
>> machines and cash registers (...)
>Thanks for that interesting piece of history! Nice insight into the workings of
>unit record equipment, a quite fascinating category of data processing in itself.
>My contribution however was not targeted at the IBM equipment thread, btw.
I realized that, which is why I left the original subject line. I just thought it was
a relevant and interesting link to the other thread about IBM punch card equipment
which was very similar in function but replaced manual entry with punched cards;
the second part of my reply dealt with the type you're talking about.
"Chuck Guzis" <cclist at sydex.com> wrote:
> "Roy J. Tellason" <rtellason at verizon.net> wrote:
> > This stirs a vague recollection of an old mechanical adding machine I
> > once had, the kind that had a big rectangular array of buttons instead
> > of just a "10-key" set of numbers. I have *no* idea how it stored a
> > number in there, though.
> When you mention the big array of keys, I think of a comptometer.
> There's a nice discussion on the web:
> But the item I'm thinking of was alphanumeric, more like a Teletype.
Yes, exactly that is the class of machines I meant. There were similar ones which printed on a platten carriage mounted behind the adding machine body, and some of the latest electromechanical models had a "type box" as a means of commenting the ledgers, invoices - whatever. The letters were assigned as secondary functions to some of the keys and the machine would print those instead of accepting numeric input when it was in a column definded for comments (which was done by sticking pegs into a programming board moving together with the carriage).
And those were the "posting" or "accounting" machines I was talking
about; in the Burroughs line that I worked with, the electro-mechanical
ones equivalent to the IBM punch card equipment we've been discussing
were the "Sensimatic" F series, programmed by a removable program panel
with two sets of "pins," one that determined the actual operation to be performed
and sort of equivalent to the IBM patchboards, and another to control
carriage movement (sort of equivalent to the forms control tapes of an IBM
40x). The panels had a selector knob which rotated the tab stops to four different
sets of positions and shifted 4 sets of program pins sideways slightly, so that one
panel served for four "programs" and of course you could have as many panels
as you needed. Incidentally, Fs could optionally also punch PPT & cards.
I had three of these at one time, but scrapped them all long ago.
The later electronic versions were the "E" series; a good brochure with
pictures of a type of computer largely ignored in the various histories
(although there's a brief mention in The Encyclopedia of Microcomputers),
with core memory and magnetic stripe & PPT/EPC I/O, can be found here:
(Chuck: change the colour, remove the cabinet on the left and put it on tubular legs
and you've got the picture you're looking for - remove the alpha keyboard for one
of the older numeric-only models ;-)
This is a fairly small one with the electronics in the desk itself (although you
can see the thick cable connecting the console to the processor), and it is still
programmed with the same type of program panel; the cabinet on the right is
a 4003 auto-reader for magnetic stripe cards, usually master file records whose
data was usually merged/combined with the data on the mag stripes of the
transaction cards feeding through the carriage. Larger models (E2000 etc.)
had a separate electronics cabinet the size of a large freezer.
Come to think of it, I still have the desk from an E1200 I scrapped long ago which
is presently supporting a Cromemco System 3, and also still have one of the tape
perforators you can see on the right side of the E1200 in that brochure, as well as
a few other odd parts...
The "E" series was later replaced by the "L" series which finally abandoned
the full keyboard and used "normal" machine language programs loaded from
PPT or ledger cards (and, later, cassettes). That was the machine, incidentally,
which got me out of being an "employee" and took me into self-employed
programming, consulting and support, which is what I've been doing for the
last thirty-odd years, so I have fond memories of it...
The last Burroughs machines of this class were the B80 & B90 which used
disks and represented the transition to more conventional computers, with
optional displays and terminals, datacomm etc.
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