Originally Posted by
Ace
I did the swap when I got my IQ-501 a few years ago, but have since reverted back to the UMC clone chips as I have an AV Famicom and Twin Famicom (and will soon get an original-model Famicom). The UA6527 is the clone CPU while the UA6528 is the clone PPU.
This eliminates the reversed duty cycles problem that plagues most Famiclones, but the audio output will be distorted (at least, it was distorted on mine when I put in a 2A03 in place of the UA6527). To fix this, you will need to replace a few resistors. I don't have access to my IQ-501, so you will have to provide a picture of the motherboard so I can show you the resistors in question and what to replace them with.