Marty,
The game plays fine. I can't wait to play it with sound !!
I have done a matrix switch test and found I needed to replace the 2 x PCB's which make up the opto ball sensor.
Every other switch works fine.

DJ,
Thanks for the tip on the Leon Test Eprom.
That will keep me occupied for a few weeks.... ;- )
I already have 3 x 6821's in the mail.
I was going to blindly replace them, but now I see I can run the Leon's test EPROM.

Rich