Ricoh RF5C164 revisited
Posted: Fri Jan 07, 2022 4:57 pm
(Not sure if this belongs here or in the SegaCD subforum)
I've been cleaning up my Ricoh RF5C68 / 164 core the other day. There are a couple of things I would like to discuss:
1. The RF5C164 can access 128KB of memory (according to the manuals), meaning the internal processing will use 17.10 fixed point instead of 16.11
Is anyone aware of a system that uses 128KB PCM RAM ? Would like to add this to my core, but I need a test system for validation.
2. There also appears to be a RF5C105 version, similar to the 64 / 164. I've been unable to find any datasheet, or rather, any information at all. Does any info exist for this model ?
3. What happens when you loop to PCM loop stop data (PCM sample = 0xFF). Will the channel stop sounding, or will it process the PCM sample and continue operation as normal ? I have yet to find a game which does this.
4. The RF5C64 outputs 10-bit data to the DAC, while the RF5C164 outputs 16-bit data. Not really significant but important to know if you want to support both models.
I've been cleaning up my Ricoh RF5C68 / 164 core the other day. There are a couple of things I would like to discuss:
1. The RF5C164 can access 128KB of memory (according to the manuals), meaning the internal processing will use 17.10 fixed point instead of 16.11
Is anyone aware of a system that uses 128KB PCM RAM ? Would like to add this to my core, but I need a test system for validation.
2. There also appears to be a RF5C105 version, similar to the 64 / 164. I've been unable to find any datasheet, or rather, any information at all. Does any info exist for this model ?
3. What happens when you loop to PCM loop stop data (PCM sample = 0xFF). Will the channel stop sounding, or will it process the PCM sample and continue operation as normal ? I have yet to find a game which does this.
4. The RF5C64 outputs 10-bit data to the DAC, while the RF5C164 outputs 16-bit data. Not really significant but important to know if you want to support both models.