[Coco] 68/63-09 Piggy Back

[John B]

I would love to see someone design a board that holds both and has dip
switches for selection.  Maybe someone can layout a design and upload it to
OshPark.

On Tue, Oct 31, 2017 at 6:59 PM, Joel Rees <joel.rees at gmail.com> wrote:

> If I were going to go to the trouble to do that, I think I'd go ahead and
> pull the 6809, and wirewrap a perf with headers to solder into the
> mainboard, both CPUs socketed, and appropriate dipswitches to select. Maybe
> even work out a hotswitch.
>
> Might even go along with a front panel interface mod.
>
> 2017/11/01 1:44 "Tim Fadden" <t.fadden at cox.net>:
>
> I was looking for some other info in my coco files and ran across this. I
> remember someone asking about it, so here goes.  I haven't personally tried
> it, but see no reason it shouldn't work.
>
> You can stack a 6309 on top of your computer's existing 6809. Here's how...
>
> Cut pin 39 (TSC) of the 6809, leaving a small piece sticking out of the
> processor so you can solder to it.
>
> Take a 40 pin IC socket. Cut off pins 5, 6, 33, 36, and 38. Bend out pin 39
> so you can solder to it.
>
> Stack the 40-pin IC socket on top of the 6809. Solder all of the
> corresponding pins together. DO NOT solder the pins 39 together.
>
> Now you have two options:
>
> 1.    Solder a wire from 6809 pin 39 to +5V, and another wire from socket
> pin 39 to ground.
>
> 2.    Solder a 4.7K resistor between each pin 39 and +5V. Then take a SPDT
> switch, connect the common contact to ground, and connect each end to a
> separate pin 39.
>
> In either case, finish up by plugging the 6309 into the socket. If you
> picked option 1, you now have a 6309 system. If you picked option 2, your
> system is now switchable between the 6809 and the 6309 (before power-up -
> not while running!).
>
>
> --
> Tim Fadden
> "Hey Schmidt, don't forget about the six P's.
> Proper Preparation Prevents Piss-Poor Performance!"
>
>
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