I recently went through this special sort of breadboarding hell to diagnose an Apple][+ rom set
I'm sure there's a better way, but this is my first time so I figured it would be a good learning exercise.
The "Testing Apple II Europlus ROMs" article is a good start, and I agree with the OP that it's a tiny bit fuzzy. To clear things up a bit:
- According to "The Apple II Circuit Description" CS3 should be LOW, so tie it to ground
- CS2 is active HIGH, so we use an inverter to drive it via CS1
- Connect all pins except 18 & 21 to the reader 1-1
- Now preset your eprom reader to a 2716 and read away...
Here's the rig that ended up working for me:
p.s. Bonus info, I found a
tasty link here discussing apple ROMS. In a plot twist, the Apple Character ROM reads 1-1 as a 2716 without any trickery!
p.p.s. All my ROMS were good except for F0 which appears to be DOA. Now how to replace it is my next adventure. The link above may be the key …