[Coco] DE1 arrives

[Frank Swygert]

There will be no way to disable circuits on the CoCo board and install a 
DE-1 along with it in the same case. It's a matter of removing the 
original CoCo board then installing the DE-1 -- if it will fit. Bringing 
the ports to the back will likely require extension cables as the ports 
sort of surround the board, not all on one side. Plus there will need to 
be an expansion adapter to get CoCo joystick and other ports on the 
board. It will work without those, of course. Using the Coco keyboard 
will be a challenge, unless that's included on the expansion board or 
there is a parallel input on the DE-1 that can be programmed to the 
keyboard PIA. ?A better bet would be to get a mini PC keyboard and 
modify to fit the CoCo case, maybe a laptop keyboard. I don't think the 
laptop boards have the control circuitry on them though, just bare 
keyboards.

The adapter board shouldn't be a problem. I think I'd just make it to 
plug to the DE-1, maybe using a short ribbon cable, but directly will be 
fine. If the target changes make an adapter board to plug between them. 
Ribbon cable may not work due to noise. Or change the adapter board 
connector and make more than one version (I know, different PCBs, higher 
cost). I'd think that the I/O area would be kept the same with 
additional I/O added on another connector or extended to either side of 
the existing connector for some backward compatibility, but the newer 
generation might be different enough to make that impractical. Either 
way, it can be handled later. Targeting one type/brand board is a good 
idea to start with though. Maybe make the PCB layout PD or GPL licensed 
so others could change target boards.

-- 
Frank Swygert
Publisher, "American Motors Cars"
Magazine (AMC)
For all AMC enthusiasts
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