6502.org

Hello! Really hard to tell what’s happening… does it do it consistently?

Just a super random idea, but maybe check the wiring for the A4 address line on your board to see if anything came loose… I wonder if perhaps it’s floating and the CPU ends up reading the data at $8018 instead of $8008–you’ll notice that the data at that address corresponds to what you’re seeing. Might be worth stepping a couple more times more to see what data shows up on the bus; that might give you a few more hints about what’s going on. Good luck!

Do not only check for loose connections, but if you have a multimeter, do a continuity check on the address lines between CPU and EEPROM. You might have swapped some address lines (like CPU-A3 going to EEPROM-A4 and vice versa).

Is there any chance you could post the assembly rather than the dump if the ROM. I appreciate that you may not actually have an assembler but if you are following Ben's videos you should have access to a transcription - I'm pretty sure he makes them available.

EDIT: Forget that. I think CountChocula is on to something - check out the A4 connection. It seems to read a byte 16 (decimal) on from where it should.
BDD, the 6522 is mapped starting at $6000 on these boards.

Welcome, feven! (Slightly odd that your head post here looks like a copy-paste of speculatrix's earlier thread. and you've used the same title for your new thread here.)