Sourcing machines from other companies


In the 1960s and early 1970s, in order to fill gaps in its product range, Sumlock marketed some machines designed and manufactured by other companies.

In early-1960 Control Systems Ltd. acquired the English operation of Comptometer Corporation of Chicago, U.S.A., including the trademark and the right to the "Comptometer" name in Britain.  Sumlock mechanical adders replaced Comptometer Corporation's standard Comptometers for sales world-wide and the Comptometer Corporation's Comptograph ten-key add-lister was added to the Sumlock range.


Nick Law gives a good idea of how Sumlock ANITA became involved with accounting machines made by other companies, especially the RUF Visible Record Computer:

"In 1969 I was employed by RUF UK in Horley, Surrey, when it was taken over by Sumlock and later moved to Haywards Heath. The RUF manager had coined the term 'VRC' (Visible Record Computer) to emphasise for UK managers the fact that all forms used by the RUF computer systems could be read by HUMANS - as well as computers (so, if the computer programs failed, accounting data could always be recovered). Accounting systems were very varied in the UK and when computerised, programs had to be individually written for each customer - in the rest of Europe, the 'RUF Bookeeping' system was mainly used.

The 'RUF Praetor' computer was manufactured solely for RUF Buchaltung (literally RUF Bookeeping) of Zurich, by 'Nixdorf Labour Fur Impulstechnik' in Paderborne, Germany. A similar computer system was made for the firm 'Wanderer' in Germany (which I believe was sold as the 'Logatronic' by Sumlock). The Wanderer varient used slightly different electronics, but the main difference was that the RUF Praetor was normally fitted with a relay-operated form-feeding attatchment (RUF 'Intromat 54') allowing invoices to be produced, while updating the accounting ledger card records at the same time. The system looked very similar to the picture of a Logatronic system - the keyboard and IBM printer were recessed into a desk - but the printer had additional fittings to support the 'Intromat'.

Heinz Nixdorf (the Nixdorf founder) decided to buy Wanderer around 1969 and soon produced new '820' computer systems, different from the Wanderer and RUF systems, but using the same basic electronics (an early microprocessor system). RUF then commissioned an ex-Nixdorf engineer (P. Frech) to produce a replacement for the Preator, which was manufactured in Trossingen, Germany by Hohner (where I attended courses & met P. Frech). At the time, I was repairing Nixdorf and Hohner computers and developed a paper-tape punch and reader system to replace the (very expensive) IBM 80-column card puncher and reader used on some systems. A high-speed paper tape system could read data into the computers at over 2000 characters per second but required considerable modifications to the operating system.

The Hohner system (shown as a Nixdorf VRC on the website) was fitted with a fully electronic RUF 'Intromat 70' which could read customer accounts data from a 'magnetic stripe' on the side of a ledger card (similar to the stripe on a credit card). Hohner used a similar IBM Selectric printer to Nixdorf on their RUF VRCs, but it was mounted differently to allow for the larger Intromat 70. Computers at that time had a very small memory capacity, so it was not possible to store all customer data permanently in memory. The 'larger' memory fitted to computers used to write original software (a 'magnetic core store' of about 8 kiloBytes) cost over £4000 (GBP)!.

In the mid 1970s, Hohner tried to produce their own magnetic cassette computer systems, using a Hermes printer, but these were not very successful and the Hohner factory was sold to Nixdorf.

Meanwhile, I had been transferred to development work for Control Systems (but still worked at Haywards Heath). I developed new paper-tape systems and memory stores for the Hohner systems, Interfaced printers to to early intelligent terminals (never marketed) and then was introduced to the Anita Business Machine development. Norbert Kitz (my ultimate senior manager) decided that I should learn the workings of the integrated circuits that he designed for the later ANITA calculators, and I did various development on the programming system. I also assisted a programmer who wrote a special emulation system for the ABC (ANITA Business Computer) which ran on the Hohner machine. This emulator simulated the logic of the Anita LSI chips, which sometimes gave unexpected results when computer controlled instructions were carried out in certain orders (a common problem with later processors). The result of this work was that the hardware (integrated circuits) of the ABC had to be modified.

Rockwell changes
When Rockwell management took over Anita and Control Systems, various Rockwell managers visited Haywards Heath and were somewhat surprised at the microprocessor development I had been involved in. Further development of hardware and software was halted, as the integrated circuits used were not compatible with those produced by Rockwell IC plants in the USA. Work on the ABC was also halted, as it was not considered to be advanced enough for a new computer system. A friend who was working at Control Sytems later told me that all ANITA equipment was declared to be out of date and worthless, so was dumped. The first part of Sumlock to be closed was however the Haywards Heath office.

Some of the former emloyees (myself included) used our redundancy payments to start an office in Haywards Heath, which continued to supply service, software and paper forms to customers throughout the UK. We then negotiated a contract with RUF of Zurich to market some new computer systems, made by Hermes in Switzerland (where I went for courses). These systems used a 20 character-per-second ball head printer, but later systems (and Hohner sytems) used a 200 character-per-second needle printer. Ruf also introduced another computer system from Austria, developed by another ex-Nixdorf engineer named Muller. This was the CTM system - much more like a modern, networked system, using hard drive storage. We also later became Commodore PET dealers!

The Nixdorf system used a very simple processor which would now be called a RISC (Reduced Instruction Set Computer). It could carry out an instruction In less than one microsecond - at the time when the first Intel 8008 processor took at least 12 times longer!

The Commodore PET used the 6502 processor from CBM subsidiary MOS technology - but also produced by Rockwell!

Despite the disapproval by Rockwell of magnetic core storage technology used on the Nixdorf and Hohner computers, a very similar storage system was used on the Luner Landing Module - because of its extreme reliability! Rockwell should have known of this, as they got the Space Shuttle contract.

Around 1971, I was shown a prototype calculator, which had been test marketed in the UK by RUF. It was designed by Nixdorf in 1965 and used the same microprocessor system later used for the RUF Praetor an Wanderer systems, but was quite compact and drove a mechanical printer, mounted on top.
It looked rather like the Wanderer Conti, But the base was much deeper, as it contained the complete, original transistorised Nixdorf microprocessor, with a dedicated control program and magnetic core store RAM memory (similar to the components used in the early Wanderer and RUF Preator computers. The printer appeared to be similar to hand-operated calculators of that period, with a motor added, plus micro-switches under the keys and some solenoids to allow control by thyristors in the processor input/output system.
I only saw one (minus covers) which had a processor fault I was asked to fix, So I am aware that the processor was identical to the early transistor model used in the RUF Praetor VRC (later units used a more compact integrated circuit arithmetic unit).
The programmers who tried to assist the marketing of this machine told me that it could not be marketed, as it was PROGRAMMABLE so as to be able to carry out quite complex calculations. The concept of being able to program your calculator was just too futuristic at the time - customers could not imagine that they could learn to do this, so the project was a failure!"

© 2013 Nick Law.



Sumlock also marketed sophisticated scientific, electronic, programmable calculators manufactured by Compucorp, which extended its range of models.


There is further information about calculators and accounting machines made by other companies in the section Calculators Made By Other Companies.

The Bell Punch Company & the Development of the Anita Calculator
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