Tom,

Frankly it is amazing and a credit to you that my Kflop has survived the last two years of abuse in so many different configurations with dubious power supplies and my electronics experiments!

However....I had a over-eager play with a new (to me) 1982 Denford Easiturn lathe with limited documentation for the 8086 processor and gubins (I have been surprised that I found no valves).   I discovered that the logic signals to the stepper driver units are 12V along a little later than would have been timely and unfortunately had already wired up the Kflop and I had mis-identified a connection:(

I then used the same KFlop using a KStep board attached by JP7 and the lathe sprung very happily into life, so I suspect the damage to the Kflop board is limited but wonder what I am going to discover later..  I am confident there is no step and direction signal on JP4.

The 12 volts will have gone to JP4 :(

Is there a test procedure that will be quicker than me testing every IO to determine the extent of the damage? 

I suspect it is going to be fine for the XZ stepper lathe without repair...

best,

Jon