Gemini Multiboard - the Logical Route

Here's an unusually-fun advert for Gemini's multiboard collection, showing a cheapskate route, an esoteric route to "Sky High Prices Inc", and, naturally, the Logical Route from the 80-Bus Station, via a CP/M petrol pump dispensing software, to Gemini Multiboards.

The Multiboard concept started out at [@Nascom/Lucas|Nascom] as a contingency plan in case the receivers sent in to rescue the company failed to find a buyer, with two boards - the G811 CPU board and G812 video board - essentially becoming a non-Nascom replacement for the Nascom 1 and 2 micros.

John Marshall - the founder of Nascom - ended up taking the boards with him and starting Gemini Micro, launching the Galaxy 1 microcomputer as a result.

This was built around the GM811 CPU, GM812 Intelligent Video Card and the GM829 floppy-disk controller/SASI multiboards.

The Nascom 1 and 2, as well as the original multiboards, used the NASBUS plug-in interface format, with the success of the micros - the Nascom 1 was at one point the UK's most popular kit micro - leading to a small industry growing up around it.

However, when Nascom was eventually sold to Lucas, the terms of the sale did not allow the use of any name using the Nas prefix, and so Gemini ended up renaming it to 80-Bus, hence the 80 Bus Station in the advert.

A reasonable collection of boards had built up by this time, from a range of companies including Gemini itself, Arfon Microelectronics - a company formed by former Nascom marketing head Kerr Borland - and EV Computing Ltd with its IEEE 488 cards. 

The advert shows around 15 different boards, but there were around a hundred in total, any with the GM prefix indicating that they had been shown to work on the Gemini Micro 80-Bus[source: https://nascom.wordpress.com/gemini/the-definitive-gemini-numbers-list/]. 

The Multiboard concept allowed for a significant range of [=gemini_percw_dec84|system configurations], although existing Nascom users had their own starting point on the Logical Route as they already had a CPU and video card.

It also shows one of the suppliers as Interface Components Ltd, which appears to be another of John Marshall's companies, which he had set up in the late summer of 1980[source: "Nas comments", PCW, September 1980, p. 37-38].

Computer companies which sold bare boards in any form loosely fell into two distinct camps: those like Gemini or little-known Karadawn which offered lots of individual boards which plugged into some sort of backplane, like S-100, and those that offered single-board computers instead.

The former offered lots of configuration options, often with choices from various manufacturers, but at the cost of size, power requirements and reliability - with many interconnected points of failure.

The latter often sold themselves as more reliable and compatible, as everything was built together with fewer interconnections, but at the cost of less adaptability.

Modern desktop computers are a hybrid, with highly-capable motherboards with most things - like networking, video, disk controllers and memory - on board, but with the option to plug in specialist or better cards if needed.