Taking more looks at the binary code again these days. It took an epiphany to realize why the pcm drum code was accepting program change; now I know how to change the auto-accompaniment via MIDI ;-) I'm up to simulating code on another computer how to fully understand the bit shifting for the actual...

I wanted to let everyone know I was still around and -then- saw galibert's response. That's a pretty good idea in fact. :) I'll have to see what I can do about midi interrupts since the whole program is event-driven. There's got to be a timer interrupt in there somewhere as well but it should be mos...

Just letting everyone know I'm still around. Real Life(TM) stuff has kept me off this for a bit while we transition things here to winter mode. :) Still digging in the RYP7 code. Have a screenshot of what compilers do when not properly told how to optimize code. The system changes ROM bank, gets 3 b...

Thanks for the info. The schematic for the pss480 is attached. I also have schematics for the psr-16 and psr-36 at this point, but I haven't scanned and stitched them. Anyone know of a chain that can scan big sheets of paper in one go? :-D Interestingly, the psr-36 has stereo outputs from the OPU to...

Considering galibert's info, I'm believing that the FM hardware is present at a base address of 0x200. I've attached a screenshot of a bit of code run during reset that presets some variables and other hardware before entering the main loop. Galibert, does this seem to line up with the addressing be...

That's great info, thanks a bunch! I'm not at all familiar with FM chips so notes like these will be very helpful, especially when the FM hardware in question is entirely undocumented ;-) In other news, I did scan and stitch the PSS-480 schematic. I'm unsure if posting it would be in violation of an...

Spare time this weekend was largely fixing broken references in Ghidra. I'm entirely inexperienced in using overlays with Ghidra, so calls to the banked ROM area simply don't get properly linked in the disassemblies. This results in areas not being disassembled in the banked area and not cross-refer...

Hey all, Pardon the radio silence. It's been deep code dive mode the last few sessions and that leaves me quiet :D In working through the midi input processor I identified the buffer used to store incoming data and then process it. Interesting useless note, the PSS-480 will only sound notes from 24 ...

The locations of the 7-segment LEDs are located by examining code that presents errors to the user. LED display is numbered right to left: Digit positions by offset 6 5 4 1 0 Not sure if positions 3 and 2 are used anywhere but they're apparently not on the front panel Unsure yet what controls the de...

Calling and testing via sysex is probably a better idea. I haven't found the sysex receive code yet, but I did find the midi input port, so that's a great start :) tl;dr MIDI in is at 0x320. I still need to work out the status and control registers, though I believe I know where they're at. :) Attac...