The online community for MiSTer FPGA enthusiasts
https://misterfpga.org/
Hey! Just wondering if there was any more on the subject of hybrid in ao486. It's so great to have this core, it's just slightly underpowered for a whole separate world of applications that would surely benefit from some hybrid speed improvements.
Was there something we could test if there was still some activity on this?
The only hybrid CPU project I know about is for the Amiga, and that seems to have fizzled pretty hard.
Yeah, it seems like there's too many bottlenecks for hybrid emulation to really be useful.
As mentioned, emulating the CPU in software didn't go very well in the case of Minimig. Also note that there basically aren't any x86 emulators in the first place that are both accurate and fast.
It would make more sense to improve the FPGA code than to introduce any kind of software emulation into the core. This could make the core both faster and more accurate.
The main bottleneck is the ARM CPU on the MiSTer is not very fast. Its similar to a Pi2 and the CPU is already used for many special features, so even freeing up one of the two cores on the MiSTer CPU was problematic. It might be possible to connect a Pi through the RAM GPIO, an alternative to the RAM GPIO would have to be found, but there would probably be other bottlenecks that would then be problematic as well.
I see many new projects using the Pi Pico for various old-school enhancements. Has anyone considered using the Pico as some sort of accelerator for the MiSTer? Do we even have any free I/O on the board for such interfacing?
The Pi Zero can be used to emulate a Roland MT-32, communicating via a virtual MPU-401 interface.
Not sure if this is the answer you are looking for.
Yes it communicates over serial...
MIDI operates at 31250 BPS which is way way too slow for a CPU.
The audio is sent back via a faster serial connection, however it is also way to slow...