Is it possible to replace an AV Famicom RP2A03H CPU with an NTSC NES (front loader or top loader) RP2A03G CPU ? I thought it would be possible since my understanding was that the "H" is just a newer revision.
I searched the wiki and our forum and was unable to find an answer to my question. The closest I could find was the topic: 2A03 Revision H and this document: 2A03 technical reference.txt
After some googling around I came across a few data points about some revisions. Not sure if this is accurate or not.
Anyway, I had a defective AV Famicom CPU (garbled video), so I tried pulling a CPU from an NES top loader as a replacement, but it didn't exactly work. I could hear audio, but would get no video output. I thought perhaps they were incompatible, so I ordered a replacement RP2A03H CPU, and got the AV Famicom back to working order. For grins, I installed the RP2A03H into the top loader to see what would happen. It worked just fine with full audio and video. Does this seem odd to anyone? You can put a AV Famicom CPU into an NES, but not the other way around?
As an aside - I have a bunch of extra RP2A03H CPU's if anyone is interested. There was a minimum quantity order, so I had to buy a bunch of them.
I searched the wiki and our forum and was unable to find an answer to my question. The closest I could find was the topic: 2A03 Revision H and this document: 2A03 technical reference.txt
After some googling around I came across a few data points about some revisions. Not sure if this is accurate or not.
Quote:
The differences between RP2A03 reversions is well documented and known.
RP2A03G is the only cpu that came in NTSC front loaders
Famicom has 4 revs, E - H.
E - don't recall
F - missing looped noise playback mode
G - fixed long / short period noise select bit bug
H - dont recall
All RP2A03 cpu will execute code the same
RP2A03G is the only cpu that came in NTSC front loaders
Famicom has 4 revs, E - H.
E - don't recall
F - missing looped noise playback mode
G - fixed long / short period noise select bit bug
H - dont recall
All RP2A03 cpu will execute code the same
Anyway, I had a defective AV Famicom CPU (garbled video), so I tried pulling a CPU from an NES top loader as a replacement, but it didn't exactly work. I could hear audio, but would get no video output. I thought perhaps they were incompatible, so I ordered a replacement RP2A03H CPU, and got the AV Famicom back to working order. For grins, I installed the RP2A03H into the top loader to see what would happen. It worked just fine with full audio and video. Does this seem odd to anyone? You can put a AV Famicom CPU into an NES, but not the other way around?
As an aside - I have a bunch of extra RP2A03H CPU's if anyone is interested. There was a minimum quantity order, so I had to buy a bunch of them.