31–37 of 37 posts
Awesome work! I love the care and attention that people put into understanding these devices. I'm currently in the middle of a vintage synthesiser hacking project as well. Last year I made a fully annotated disassembly of the Yamaha DX7 firmware, and did some other technical analysis of the synth. Since then, I've been waiting for a chance to put this knowledge to good use. I found a DX9 on a local trading site, and…
https://dsp56300.wordpress.com
Pretty astonishing bit of reverse engineering there ..
Awesome work! I love the care and attention that people put into understanding these devices. I'm currently in the middle of a vintage synthesiser hacking project as well. Last year I made a fully annotated disassembly of the Yamaha DX7 firmware, and did some other technical analysis of the synth. Since then, I've been waiting for a chance to put this knowledge to good use. I found a DX9 on a local trading site, and…
I browsed through the repository as discovered by colejohnson66 downthread https://github.com/ajxs/yamaha_dx7_rom_disassembly . This is an example of superb, meticulous, lovingly documented work. The kind of thing you don't see every day, congratulations. The attention to detail is really just chef's kiss, starting with a really good repository name (a small thing, but still), continuing through clear and apparently…
Unfortunately it's impossible to know how well-documented the original assembly was. I've poked around in some of Yamaha's other synth firmware from the same era, and there's some reuse of code between them. That suggests there was some shared documentation, and tooling available between teams. Speaking of documentation, and naming: The placement of functions within the binary probably hints at the organisation of the project, and how things were named, however it's hard to tease out the abstractions they were working with after the fact.
This was my first project in 8-bit system programming. The Hitachi 6303 manual has some suggestions to use for project documentation that were even more comprehensive. I'd love to know more about how engineers worked in this era!
Also, your project looks amazing! I'll definitely give this a good look!
Awesome work! I love the care and attention that people put into understanding these devices. I'm currently in the middle of a vintage synthesiser hacking project as well. Last year I made a fully annotated disassembly of the Yamaha DX7 firmware, and did some other technical analysis of the synth. Since then, I've been waiting for a chance to put this knowledge to good use. I found a DX9 on a local trading site, and…
Are you telling me the DX9, my first synth all those years ago, actually had more than 4 operators? BTW, another thing that made it less popular: its keyboard. It didn't have velocity sensitity, nor aftertouch. Or is that also a ROM-upgrade away?
Earlier quoted context omitted.
> Last year I made a fully annotated disassembly of the Yamaha DX7 firmware You beast!
Found it: https://github.com/ajxs/yamaha_dx7_rom_disassembly It’s extremely documented. More than I was expecting.
Awesome work! I love the care and attention that people put into understanding these devices. I'm currently in the middle of a vintage synthesiser hacking project as well. Last year I made a fully annotated disassembly of the Yamaha DX7 firmware, and did some other technical analysis of the synth. Since then, I've been waiting for a chance to put this knowledge to good use. I found a DX9 on a local trading site, and…
Such clean and well organized work I rarely see. Painfully, I have to switch back now to my dayjob IDE.