Jo22 wrote on 2019-05-18, 15:53:

I see. Looking at some photos, it sadly wouldn't be possible, anyway. For some reason, the designers decided it was a good idea […]
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dr.zeissler wrote:

I will not modify the A2286/8 it will be like it is...I only update/change the ISA-Cards.

I see. Looking at some photos, it sadly wouldn't be possible, anyway.
For some reason, the designers decided it was a good idea to place the daughterboard directlly atop the 80286 and
the socket for the (hot) numeric processor (optional).. 😢

Hi Doc, how's it going? Did you find a solution/workaround in the mean time?
Speaking of.. Sorry for the necro. I just remembered this thread for no apparent reason.
I guess my subconscious was still working somehow on that problem.

If you haven't found a solution yet, I have an idea.

a) You could make an adapter, or rather an extension cable that goes to the CPU underneath the daughterboard (encircled in white colour).
However, where to get an PLCC "socket" from that fits inside the 286 socket?

That way, no real modifications are needed.
The clock frequency is low enough to alow for an extension cord of ~10cm or less, I think.
You could use a ribbon cable and use a carpet knife to slice it into stripes of ~5 cables or so.
In needed, it could also be folded carefully, too.

b) You can widen the standoff between the bridgeboard and the daughterboard by installing two or three pin stripes on top of each other.
Then you will have enough room in between to install some of those 386/486 upgrade chips. I mean, a few centimeters extra won't cause problems, electrically speaking.