Almost by accident I've actually managed to take some first steps with this.
All my existing designs are based on Xilinx CPLDs, which are all going out of production this month. So, I've had to throw together some test boards to evaluate other chip families in the real world. I'm using one of these boards as a platform to test the audio elements of the game cartridge idea, as its Max V CPLD is just about big enough to cope with those.
At the moment the board is providing the functionality of two SN76489 PSGs, one of which is mapped to provide compatibility with the Project Expansions sound cartridge that is emulated by Elkulator. I've modified simondotm's VGM player to work with this, it's not perfect but is good enough as a proof of concept. At the recent ABUG Scotland Derek (walkerworks) was kind enough to lend me his re-created sound cartridge, which has been most useful in validating my board sounds as it should. I'll try and make a video in the next few days, time permitting.
There's quite a lot of tunes available that use dual SN76489s, but modifying the VGM player to deal with them is beyond my limited 6502 skills. I'm thinking of making the input clock for one of the PSGs selectable, so it can potentially be used to make lower frequency tones than is the case at the default 4MHz clock. And possibly, if there's room, adding some kind of filtering and panning capability to the output, too.
All my existing designs are based on Xilinx CPLDs, which are all going out of production this month. So, I've had to throw together some test boards to evaluate other chip families in the real world. I'm using one of these boards as a platform to test the audio elements of the game cartridge idea, as its Max V CPLD is just about big enough to cope with those.
At the moment the board is providing the functionality of two SN76489 PSGs, one of which is mapped to provide compatibility with the Project Expansions sound cartridge that is emulated by Elkulator. I've modified simondotm's VGM player to work with this, it's not perfect but is good enough as a proof of concept. At the recent ABUG Scotland Derek (walkerworks) was kind enough to lend me his re-created sound cartridge, which has been most useful in validating my board sounds as it should. I'll try and make a video in the next few days, time permitting.
There's quite a lot of tunes available that use dual SN76489s, but modifying the VGM player to deal with them is beyond my limited 6502 skills. I'm thinking of making the input clock for one of the PSGs selectable, so it can potentially be used to make lower frequency tones than is the case at the default 4MHz clock. And possibly, if there's room, adding some kind of filtering and panning capability to the output, too.
Statistics: Posted by Ramtop — Sun Jun 02, 2024 9:29 pm