retr0brite not so right?

On 02/08/10 19:36, Tony Duell wrote: Agreed. As I've said, I'd rather like a SYM-1, KIM-1 or AIM-65. But given that I've talked to a couple of people who said "yeah, I've got loads of those in a warehouse, you can have one" and then dropped off the face of the earth... I'm not hopeful. Actually at this point I'd settle for getting my Jupiter Ace motherboard back from Lee Davison. Again, chance close to nil. Even getting a bare Ace PCB or a broken Ace to fix would be nice... I'd build up the bare PCB on the grounds that: - It'll be a fun evening's work - I know other people have bare PCBs and that they're not "one-off" rare (AIUI a box of them was sold off when Jupiter Cantab went bust) - As a bare board, it's as useful and as entertaining as a brick. Build it up and it becomes a whole lot more interesting. Yes, but not the sort of machine I was thinking of (a "microcomputer trainer" type thing). In some ways it is a completely evil design. Reverse engineering it is diabolically hard, and I think some parts of the design must have been conceived by a madman or a masochist. But getting the parts count down that far? Cool. The BBC is a lovely design. From an expandability point of view alone it's something that -- even today -- is worth keeping on or near an electronics workbench with a User-Port-to-breadboard cable. And if you need a few more I/Os, there's always the 1MHz Bus. They make terrific logic pattern generators, the BASIC has full floating point and a good range of math operators (I don't have a full list to hand, but IIRC it at least has sine, cosine and tangent, and possible arc-tangent as well) and the machine itself is built like a Chieftain tank. Plus if something goes wrong, it's all LSTTL or easily obtainable parts (aside from a ULA or two and possibly the SAA5050). If you had to, then there's almost certainly enough documentation (reverse engineered and otherwise) to rebuild a BBC Micro video or serial ULA. Keeping the machine running wouldn't be a problem... Well, as long as you had a supply of spare 100nF X2 capacitors for the power supply filter. Those go pop at an alarming rate, and have a rotten tendency of caking the innards of the machine with brown ichor when they do. -- Phil. classiccmp at philpem.me.uk http://www.philpem.me.uk/