I am working on a 6503 based board that I am trying to revive. I'd like to use my Fluke 9010A microprocessor troubleshooter and 6502 pod to help. I ended up buying an adapter to for using a 6502 in a 6504 socket. I double checked that adapter and all looks good as far as pin mapping. Since I am trying to debug a 6503 board I made an adapter using a pair of machine pin sockets to adapt the 6504 to the 6503 footprint. It entailed shifting most of one row down one pin and a couple on the other side. The 6503 just uses one less address like so that was left disconnected.

The /RESET line and /IRQ line flows through to the main board but signals like /NMI are just left floating. Question is if that is ok or if I should add something like a 4.7K pull up resistor on that line? Also the 6503 lacks SYNC and RDY signals and don't know if those are fine to be disconnected. What should the state of those two lines normally be for a 6502?

As it stands now the only pins to flow through from the 6503 to 6502 pod are D0 through D7, A0 through A11, VSS, VCC, clock 0 in, clock 2 out, R/W, /RES
, and /IRQ.

Appreciate any help or suggestions.

Robert

I fixed it! Just tied the two VSS ground lined together, cut the ground connection to the RDY line. And added 4.7Km pull ups on the RDY and /NMI lines.

That's great! (And welcome!)