Thanks, lisa2. Great video! I put the mouse card into slot 1, 2 or 4 with the same results. I noticed that my Apple /// doesn't like the CFFA3000 card and the mouse card installed at the same time. That's where the A3 doesn't boot. Once I remove the CFFA3000 and leave the mouse card installed, the A3 boots as normal, though it did not recognise the mouse card (I changed the slot settings for SOS.DRIVER). I'll try it in a IIGS next to see if the card is damaged.