On Fri, 19 Jun 1998, Chris Halarewich <chrish(a)knet.kootenay.net> wrote: ] I was looking around at http://www.patents.ibm.com ] ] I discovered that Commodore Electronics held the ] patent for the case of the TRS-80 CoCo2(3?), which makes me wonder if ] they designed the rest of the computer for Radio Shack. ] ] Any Edgeumacated guesses anyone...anyone :) ] ] Chris Halarewich The data sheet for the Motorola 6883 Synchronous Address Multiplexor, which is the key wonder-chip in the CoCo 1 and 2, includes a schematic that accounts for about 80% of the CoCo design. The 6883 and 6847 were clearly designed to be used together, and the rest of the design was pretty much driven by that. Of course, the CoCo does have a little stuff hanging off of the two PIA's that isn't given in that data sheet. But I'd be surprised if they had gone to Commodore for that. Of course, I'm surprised enough at the patent on the case (who would need to infringe a patent to make a rectanguloid plastic box?!), so I guess the origin of the remainder of the circuit design could surprise me too... Bill.