Right having done some fiddling, and finding that I also had a bad 74LS45 / 74LS145, I have managed to get the UM6502 worining in the Atom.
However it only works if the 8255 is replaced with an 82C55, i.e. the CMOS version.
Wonder if putting a 74HCT245 in it's databus (enabled by /CS, and connected to R/W) would let it work with a normal one.....maybe something to try later![:)]( "Smile")
Cheers.
Phill.
However it only works if the 8255 is replaced with an 82C55, i.e. the CMOS version.
Wonder if putting a 74HCT245 in it's databus (enabled by /CS, and connected to R/W) would let it work with a normal one.....maybe something to try later
Cheers.
Phill.
Statistics: Posted by Prime — Mon Feb 03, 2025 8:43 pm