1985 - Make or Break

We were struggling to get recognition of our HT1470 range – as a young company we found it difficult to pursuade companies to use our facilities – a common comment was ‘How do we know you’ll exist in 3 years time?’. Looking back after 40 years, hardly any of our customers in the 1980’s still exist! A new more professional leaflet was produced but we were now finding it difficult to continue - product development is expensive and we had no useful support and limited access to finance being a young company without a track record.

One idea I had and started to develop was for a graphics based logic system. This would use the user I/O capabilities of the 1470 along with an interpreter to allow graphical design of software 'logic circuits'. Another idea came from an IBM PC clone distributor who wondered if we could design a hand held language 'interpreter'. Both possible ideas but without the ability to pay for the design time never went anywhere.

Sentrie

Just as things looked impossible to continue, we were approached by the managing director of a local company, Huwood Electric, which had recently become part of the much larger Babcock group of companies. Huwood Electric produced mining equipment and needed a new product urgently. The requirement was for a low power supervisory alarm system initially monitoring man carrying conveyor belts which could shut down the conveyor belt should a fault condition be detected. Why low power? Electrical equipment in mines has to be I.S. (Intrinsically Safe) designed which greatly constricted electronic design, only very low power consumption, no inductors, limited capacitance, all in order to avoid sparks which could produce an explosion in a coal mine environment. A further design restriction required by the NCB (National Coal Board) was for the design to fail to safe on any single component failure. All this and they wanted it in a number of weeks in order to demonstrate it an upcoming mining exhibition!

Our original HT1470 proposal included the purchase of a Concurrent Pascal compiler which we had never been able to follow up due to the high cost – over £1500 for the compiler and a substantial sum for the purchase of an IBM XT (IBM PC with 10Mb hard drive costing over £3000!) on which the compiler would run. I saw this product design as a means of obtaining this development system.

A period of intense design and prototype manufacture then occurred as Huwood wanted a demonstration unit available for the large trade exhibition occurring in the near future. This included me working over the bank holiday and getting a ticket for parking on a double yellow line outside the office on the monday! The final design was implemented mostly in Concurrent pascal with extensions to the p-code kernel replacing some of the Pascal code to enable it to handle some of the processing required at a speed that was impossible in p-code – the 1802 processor was slow!  Our hardware protyping had used wire wrap technology previously but we had moved onto using SpeedWire to produce initial designs faster.

The product was successfully demonstrated under the name ‘Sentrie’ and early production models were installed in British and South African mines. Little did we know but the product was helping to keep Huwood Electric afloat as a company - as with many companies we have been involved with takeover / mergers tend to mean some companies just disappear and the new product gave the company a new 'High tech' profile. This actually happened to the company I worked at before moving to the university. Clarke Chapman were the largest employer on Tyneside in the 1970s and I worked in the Advanced Technology Division (ATD) designing systems for use in boiler manufacturing and maintenance. Here I was able to 'play' with the newly fangled microprocessor components and develop programming skills in machine code / assembler which I had briefly touched upon in my work on an onboard marine seismic data processing system for Shell. Before I left to work at the University, Clarke Chapman amalgamated with Reyrolle Parsons, a major turbine manufacturer in Newcastle to form Northern Engineering Industries  (NEI) - the largest North East Company. This resulted in struiggles between the various development divisions and eventually ATD disappeared. NEI were later taken over by Rolls Royce in 1989.

IBM XT

Sentrie

Sentrie with front panel removed

Sentrie Hardware System Diagram

Sentrie Hardware System Diagram

Sentrie Software Architecture

Sentrie Software Architecture