Just trying to get my head around how the PROMS are addressed in an A1
A0 to A7 are obvious. CE1 from B9 decoder as nCSF developed when A12 to A15 are high
Which gives the address range Fx00 to FxFF
But CE2 must be then low when A8 to A11 are high to give the address range FF00 to FFFF and I can't see how this is done. CE2 seems to be connected to B1 NAND gate with one input from the CPU clock and the other floating as the 6800 bits are missing ? Is it not decoded and always low meaning the PROM appears at multiple addresses ?
BTW, just got my A1 running with its keyboard tonight so ready to start playing.
Cheers for the kit UB :)