[Coco] need a mini 6551 RS-232 pak layout
Roger Taylor
operator at coco3.com
Thu Jan 15 23:10:18 EST 2009
I'm looking for someone who can help finsish designing the schematic
and board layout for a mini RS-232 pak based on the rather simple
schematics for the CoCoPro! RS-232 Pak. As some know, this is
nothing more than the schematics for the DC Modek Pak but with the
phone modem circuitry removed. It's just a 6551 and ROM mapped to
the expansion port pins. My version has an EPROM instead of the
ROM. There's 4 chips and the board fits in a standard game pak
case. The board is already designed to fit any game pak and also a
new case I'm looking at. So, the mini RS-232 pak layout has to fit
on this board. I've already got the chips layed out similar to the
DC Modem Pak's format but I'm having trouble with the trace
routing. Maybe that's because I'm not an expert at such.
The software needed is free, called ExpressSCH and ExpressPCB. If
you can use ExpressSCH/ExpressPCB and are good with design and the
6551, please submit a quote for what you think it's worth for you to
finish laying out this board and test all the connections "on paper",
etc. 6551, 2764/27128 EPROM, 74LS04, 74LS133.. that's about
it. I'll work with you to help get this done so I can send off for 4
sample boards as quick as possible. Give me an idea of what you'll
need or not need.
I've got the base layout files, and about 75% of the schematic is
drawn and some of the net connections are defined which helps
ExpressPCB reveal what pins need to be connected with traces, etc.
--
Roger Taylor
http://www.wordofthedayonline.com
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