Apollo 68040 how to properly install it on a 1200 and close the trapdoor ?

[Matt_H]

My understanding was that all A1200 040 accelerators should always be run with the trapdoor open and/or slightly elevated (you can put larger rubber feet on the bottom case). Did you previously have this system working with the trapdoor closed?

[Matt_H]

On the Apollo card the CPU sits inside the case. So the culprit is probably the heatsink of the 040 hitting the keyboard and gets pushed downwards. That thing with the rubber feets is for Blizzards, as their CPU faces outwards.

This is worth examining further. Make sure the accelerator isn't catching on the rim of the trapdoor (or anywhere else), which would subject it to pressure when the case is closed, possibly compromising the connection with the motherboard and causing the errors you described.