TheNewBrain Page

The Newbrain started life as a Z80 replacement for the Scampi (SC/MP) processored Mk14 in Sinclair Radionics arround July 1978. The decline in fortune of what was one of Sir Clive Sinclair's earliest companies, led to a major investment by the NEB (National Enterprise Board), who as time went on, increasingly controlled the company, which eventually prompted Sinclair to leave. To raise funds, for what was in fact a failing company, the NEB sold the still fledgling Newbrain project to Newbury Laboratories. Sinclair had turned his mind to producing a cheaper and more compact design than the Newbrain concept, which was to be the ZX80. However, there was an incestuous relationship betwwen these two projects, as can be seem from this extract from A New Means To An Old End by Ian Adamson and Richard Kennedy, to be found on Planet Sinclair "While the ZX80's software development can be chronicled in detail, a shroud of mystery hangs over the design of its hardware. Even at the time, Grant recalls a 'cloak-and-dagger' aura to everything associated with the machine's hardware. One possible version of the story is that Mike Wakefield, who at the time was working for Newbury to design the NewBrain's hardware, may have assisted Science of Cambridge. The hardware was not completed by the August deadline. Some participants suggest that Wakefield simply hadn't managed to design and build the circuits required, others that Newbury was threatening to cause trouble over his participation in the Sinclair project."

This problem with late completion of hardware was to curse the development of the Newbrain. Thus, over two years after it was officially announced by Newbury Laboratories, all that had been produced were a series of glossy brochures. The government Quango's that had been funding this project, got fed up and it was rescued by the British Technology Group who placed final design and production with the Grundy Group. They made a gallant attempt at production and produced two models in commercial quantities, the more popular AD, with it's built in vacuum floursecent single line display. Which looked 'sexy' but was largely useless for most practical purposes! Thinking behind this was the production of a portable system, well before the development of practical laptops. Unfortunately, the very large number of TTL circuits in the design (++50), gave a high current consumption and lead to very large ni-cad battery packs, which in turn led to an anything but portable product! The other model, A, came without the display, but was not much cheaper to produce. In retrospect, it would have been better to concentrate on a single model. Grundy in their original Newbrain Beginner's Guide unfortunately gave reference to the availability of an expansion unit, enabling vast quantaties of memory (up to 2Mb of paged RAM), a disc interface and the aforementioned battery pack. In reality none of these were in production at the time of publication and Grundy Business Systems were to go into recievership before any of them were produced in serious numbers. Thanks to a clever design, the fonts and language routines were kept in a separate small ROM. This meant that many different foreign languages were supported from the start. Some of the greatest overseas sales in fact went to Holland, and a Dutch company, Tradecom International BV, bought the design from the recievers. They went on to manufacture large numbers, including a disc interface and eventually a hard disc interface and a network system very like the BBC's Econet system as well. As a result many of these sytems were sold to Dutch schools, as with the BBC micro in the UK. This accounts for the only existing, large Newbrain User group, the "De HCC Newbrain gebruikersgroep", located in Amsterdam. This site has a vast amount of online software available in it's archive. These include programs for the standard, unexpanded A or AD, as well as CPM and programs for the 96k machines with an expansion unit.

My Newbrain History

My first contact with a live Newbrain came in early 1983, when I was working as a Physics Teacher at South East London School, Deptford. To escape the depressing environment of a moribund school, I attended a large majority of the then ILEA's computer courses, including the Micro Interfacing course at the Black Prince Road, Design & Technology Centre of blessed memory. One evening a fellow student brought in his new Newbrain AD. We looked in awe of it's proper keyboard and expansion interface, as we were working with the flabby keys and unreliable edge connectors of the 48K Spectrum! It was thus with some interest, that I subsequently saw in Greenweld's Surplus Catalogue, then only a couple of folded photocopy sheets, a group of Newbrain items. These included the populated main board, the RAM board with all it's chips, but unsoldered, a range of keyboards of any language other than english, the user manual, the power suppliy and photcopies of the circuit diagrams and schematics. Greenweld had obviously bought up the remaining stock of unused components from Grundy's Receiver. I bought one of each item and assembled a Model A, which worked from first power up. I subsequently bought another powersupply, as I found that they provided a far cooler and more reliable supply for my QLs. These subsequently all gathered dust in my shed, as PCs with floppy discs then caught my attention. Fast forward to last year, when I retired due to ill health and had time on my hands! I found the dubious pleasures of eBay and bought fairly cheaply a non working Newbrain, ostensibly to provide a case for my home made product. I may well have done that, if some kind soul (Ant Goffart) had not emailed me with the information that non-booting Newbrains are easily repaired. I subsequently found where he had got his info from, that is on the Newbrain-gg site! I have subsequently repaired two more Newbrains, using the same method, that is to replace the two 10 microFarad capacitors controlling the reset circuit. These are small electrolytics, which dry up with time. In most cases, this does not matter, as the capacitance merely varies. However, in timing circuits it is critical, hence the dead Newbrains. I have now replaced them with Tantalum Bead capacitors, which should outlast many of the other components.

The GRUNDY NEWBRAIN