Doug Spence wrote: Large keyboard on a machine that early is a new one on me! case 1000035, Blue trim was dropped fairly early - both the machines we had at school were black trim - as was the rebadged cassette deck with the lift-the-lid eject mechanism, the latter being replaced by the C2N. I had always assummed that 1000035 meant the 35th machine with the 220-240V power supply. Help. We need the Anderson. Larry, where are you? Can you help on this? got No rubber cups. Rubber cups or domes always in my experience give some sort of mechanical hysteresis when you press them. All PET keyboards I've used are smooth until they hit the stop. Small keyboard had little black rubber pads set into the plastic mouldings of the keys. connector. present. of Only the lack of power. Flying lead from cartridge to 2nd cassette port is the usual solution AFAIK (it's what I did on my RAM expansion). No, I've never heard of ROM cartridges like this but I've met other things I think. ROM expansion usually went inside... 24K POKE Indeed I have. Tony Duell helped with one or two tips, I think. Such as, 65256 doesn't work, use 62256 instead. And the way of avoiding the need for inverters if you use the right sort of gate when re-encoding your address (but I may have failed to implement that). No, it's software. It was a feature that was supposed to prevent inquisitive geeks disassembling the BASIC ROM between $C000 and (I think) $E7FF. The OS ROMs, above $F000, were peekable, though, as was the I/O space in the E block. You could of course peek and poke the screen, $8000 - $83E7 inclusive. Zog! You'll have to pull block select 0 from somewhere on the motherboard then. You might as well take +5V from there while you're at it. I'll try and dig out my RAM expansion board, and work out what it did. Meanwhile, have fun! Philip.