[urq] urg computer question

[a.j.gaidos at comcast.net]

Yep, I was planning on sourcing out newer parts and improving the layout. I'm not looking to make an exact copy.

-------------- Original message -------------- 

> Anton, 
> There are actually three different variations of the MAC-02 PCA. The "RDH" 
> schematic is based on a revision of the version 1 PCA. There is a local 
> gentleman that has a copy of the actual schematic for some version of the MAC-02 
> from Hitachi, but I have yet to arrange getting a copy of it from him, although 
> he has offered. The circuitry itself is pretty basic, so I usually don't even 
> bother with the schematic. FWIW, the major components on the PCA have been NLA 
> for over a decade, with little or no documentation as to their exact function or 
> specs. 
> 
> I know where you are going with this, but personally I think that the best 
> solution would be to make a replacement PCA that could run improved code with 
> modern components. I don't see any reason to duplicate what is a poor design to 
> begin with. While I was at it, I would fix design issues like the stupid low 
> resistance intake air temp sensor and replace the MAP sensor with a modern 
> Motorola part, etc. You might as well add some rudimentary diagnostics and 
> external programming while you are at it. Maybe that is what you have in mind. 
> I do believe that the main connector is still available from AMP. 
> 
> As to the mechanical specs for a CAD, you might as well make those yourself. 
> That's easy. I doubt Hitachi even has those anymore. 
> 
> Steve 
> 
> 
> 
> One page schematic. I was expecting more. Now I need a parts list to source 
> parts and a mechanical drawing for the board outline, keepout areas, mounting 
> and tooling holes. Fixed components like connectors would be a must as well. 
> 
> ... I suppose you all see where I'm going with this. 
>