Mechanical calculators - test-drb@ccmp.vtda.org

4 Dec 2007

M H Stein <dm561 at torfree.net> wrote:
...
  From: "Arno Kletzander" <Arno_1983 at
gmx.de>

 My contribution however was not targeted at the
IBM equipment thread, 
btw.  ------
 MHS:

 I realized that, which is why I left the original subject line. (...)
 the second part of my reply dealt with the type you're talking about. 
Sorry for the misunderstand, thanks for clearing up.

...
  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 (...)  ------
 MHS:

 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," (...)
 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 (...)

 Incidentally, Sensimatic referred to the way the program pins 
 were "sensed;" the pins were different lengths which determined the 
 operation to be performed (add/subtract/print/etc.) and different pin 
 locations determined the register number or the accumulator (sound 
 familiar?). A set of sensing pins would rise up to measure the length of 
 the program pins, and the keyboard also had "function keys" (called 
 OCKs - Operator Control Keys) for different options (normal entry, error 
 correction, etc.)

 A program would consist of steps like "Load A (from keyboard) (INP 01), 
 "LD R1, 2 and 3 from A," "SUB A from R5&6," "Punch A (OUT
2)," "IF OCK3
 then SKIP (JMP) to Step12," etc., all done mechanically with gears, 
 levers and springs of course. Programming was done with a nibbling tool, 
 a tray of numbered different length pins and a screwdriver.

 Wouldn't you love to have 20 registers today, and the ability to 
 load/store more than one simultaneously? Mind you, that was also the 
 entire memory until electronic versions came along... 
Uhh, what have I done to deserve this treatment? You make me long for those big ugly heavy
boat-anchors even more than before.
Must...go...chastise myself (before my parents do when I bring home the next one :-))

All joking aside, my collection in the field of accounting machinery is pretty fragmentary
yet: All I have is a Triumph Duplex wide carriage accounting typewriter (Wahl actuator
principle, supposedly pre-WWII) with motorised carriage return and just two registers (one
on the carriage for vertical sums, one on the machine body for horizontal sums, and an
empty shell that activates the horizontal register but doesn't accumulate in itself -
there sure must have been more), and a Triumph-Adler "TA 20 compact" electronic
facturing typewriter which pretty much looks like a Selectric with a numeric keypad, a few
extra lamps and all dressed in white.

The older one was a dumpster find and is unrestored as of yet - there's a load of
rust, dirt und grease gunk inside and I'm not so sure if I'm going to get it
reassembled if I take it to pieces far enough to clean it out. 

The electronic machine was a present from my grandfather who was a office machinery
serviceman, it was my practice machine for the touch-typing course I took in grammar
school and it's working to this day. There is a keyswitch to select either typewriter
or facturing machine mode, the customer-specific facturing program (for which I was lucky
enough to also get some documentation; obviously the machine was used in a carpetry store)
is hard coded in an EPROM and even contains the postal adresses of some regular
customers.

Writing a new program involved some precoding on forms. Then, a cassette-based
"programming accessory" was attached to the machine, the program entered and
saved to tape. The programmer (and the customer?) could test it for correctness; if it was
accepted, the tape was sent to the factory, the program burned to EPROMs and these sent
back to the serviceman for installation. Unfortunately, I do not have that accessory, and
working out the interface for building a replacement is somewhere quite low on my priority
list.

Oh, I forgot that "GROSS U.K." restaurant cash register with key-locks for eight
waiters and dual printer for receipt and journal. This one is also working, but the case
has a few dents in it.

But something I'd really consider a find is one of those desk-sized facturing
machines, say a Rheinmetall FME series - this has a motorized mechanical four-species
calculator in the desk drawer which is electrically linked to the typewriter on top:
magnets for input, contacts for readout. My grandfather detested those, as they used 120V
DC to pick the magnets and there were lots of unencapsulated contacts within the
mechanism...

Greetings,

-- 
Arno Kletzander

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