DigicoolThings Forum

I've started planning for a Motorola 68008 CPU Card for MECB.

The 68008 is the 8/32-bit version of the MC68000 processor.

It was most notably used in the Sinclair QL computer.

Internally, the 68008 is a full 68000 processor, but with an 8-bit external data bus interface (hence 8/32-bit).

At it's launch in 1982, the 68008 was intended to enable designers to leverage existing 8-bit hardware designs and 8-bit wide memory, to enable a lower cost of entry to the new 68000 world.

This makes the 68008 a perfect candidate for our Minimalist design intentions. In fact, it probably represents the high-end of CPU candidates for our Minimalist Europe Card bus.

A 68008 CPU card would enable us to experiment with 68000 coding. Ideally, it would also be compatible with our existing 8-bit MECB peripheral cards.

To this end, my current thinking is to make a 68008 CPU card that implements the full addressable 1MB of fast memory, on-board, allowing full "no wait-state" processor speed. The MECB bus then being used exclusively for the legacy 8-bit peripheral support interface of the 68008.

The only downside of this approach will be to rule out using the later 68000 family peripherals. But, in the interests of having a powerful 68000 CPU to play with, whilst keeping with the Minimalist philosophy of MECB, I think this approach is the best fit for the MECB project.

Currently in early planning stage.

....!!

ohh, yeah...

Back in the old days after learning the basics on my Ohio C1P machines I then moved up to Sinclair QLs where the learning started all over again. Apart from the poor hardware (especially the microdrives) and slow software (68008) they had a really good and well documented multi-tasking operating system (QDOS). My QLs were pimped out with 3.5" disk drives and EPROM programmer add-ons and several software ROMs. I used to use the QL for designing custom sundials for any location and orientation. I maintained my colleagues QL for his office needs. I wonder if QDOS could be made to work on an MECB?

One of the additional boards I made was an Inmos link interface, this talked to an Transputer M212 hard disk controller with an old 5MB full height disk drive. The software was kludged up floppy-disk driver. The QL with the hard disk became a file-server talking down the twisted pair network interface to some of my other QLs. I sold most of the system to a fellow enthusiast back in around 1990 when I had moved over to PCs. I never had the same affection for them though but I did some device driver hacking and an ISA breadboard telephone interface with ADC back when Borland C was popular. I still have the card, maybee see if that still works one day ...