[Coco] Embedded CoCo

[Frank Swygert]

I'd think that a kit with a board and any hard to find/special circuits 
and software would be sufficient, though a complete parts kit would be 
nice. If the thing can function as an expansion card for the CoCo (I/O 
controller) and/or a stand-alone controller that would be great! Maybe a 
circuit or two or just the ROM would need to be changed? Even if it can 
only be built one way and not dual purpose would be fine. Development 
work could be tested on a CoCo then simply ROMed and plugged into the 
board. Or if it plugs into a CoCo anyway, why not a flash ROM so no 
actual burning is necessary?

This would be great for my glass dash idea. Since small composite LCD 
monitors are reasonably priced now, I'd like to replace the instrument 
cluster of a car with one. Program it for a normal and performance 
display, switch between the two with a hot key. Could even have a trip 
computer with a couple hot keys. Of course no keyboard, just a small 
keypad or 3-6 momentary switches. I thought about doing that with a CoCo 
a long time ago -- the joystick inputs could be used for most things, I 
think it could be wired to a variable resistance and read that. If not, 
there was the unused keyboard PIA inputs and the cartridge slot. Typical 
old style gas sending units (Ford & AMC) use 5V and read 10 ohms high, 
73 ohms low (temp, oil pressure, fuel level). Speedometer would be easy 
with a magnetic read switch (pulses). Pulses for the tachometer would be 
harder -- reading the coil firing might require some type of isolation 
circuitry. Program could take care of # of cylinder selection. Could 
always disassemble an old electronic tach to find out.

Main reasons I never did this was that big enough graphic LCD displays 
(not laptop size, 5"x7" would be sufficient, 4"x6" a little small but 
probably usable) were expensive 6-8 years ago, and the CoCo board itself 
was just to big to mount conveniently. I knew enough tricks on the CoCo 
once to pull this off, but didn't want ot put the time and effort to 
learn with a STAMP controller, plus I don't recall it having enough 
inputs. Then there was the LCD panel issue...

Have more money for an LCD now, plus cost is within reason without 
having to build a complete controller, but CoCo board placement would 
still be a big issue. Not with an embedded type though. Of course I've 
forgotten most of the programming for the CoCo now...
-- 
Frank Swygert -- Gulfport, MS
Publisher, "American Independent Magazine" (AIM)
Supporting all AMC related vehicles, 1902-1987
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