MiSTer connection?

[rhester72]

I saw that MiSTer owners (me! :) can now control mt32-pi from the OSD...but there's mention of a special connection cable? I'm vaguely familiar with MidiLink on MiSTer but assumed a standard USB MIDI adapter would do...do you have more information on the connection required?

[dwhinham]

All will become clearer over the next few days, Sorgelig (MiSTer project lead) will leap into action with a PCB design release and core updates to support it now that v0.8.0 is available.

Some details are already available in the wiki. 🙂

[rhester72]

Wow. :)

[dwhinham]

As promised:

[bzeiss]

I have started to solder sorgelig's pcb. I haven't received all the necessary components though. So far, I have only soldered the buttons, the gpio and the oled. I have a couple of questions:

1. https://github.com/dwhinham/mt32-pi/wiki/MiSTer-FPGA-user-port-connection states a number of configuration changes. For sorgelig's pcb, shouldn't the control scheme be set to simple_buttons as default configuration? I soldered the buttons to the pcb and was surprised that they didn't do anything. When I changed it to simple_buttons, they started to work (somewhat).

2. I'm wondering what the actual behavior of the rom button is. I tried it first with the "easily" available roms with the following filenames: CM32L_CONTROL.1989-12-05.v1.02.ROM, CM32L_PCM.ROM, MT32_CONTROL.1987-10-07.v1.07.ROM, MT32_CONTROL.1988-09-30.vX.XX-patched.ROM, MT32_PCM.ROM.
   With rom_set=old*, the mt32pi oled states that it selects the 1.07 rom on startup. When I click the rom button it states "ROM set not avail!" despite the fact that I expect switch between three roms. After that, I deleted the patched control rom and renamed the files to CM32L_CONTROL.ROM, CM32L_PCM.ROM, MT32_CONTROL.ROM and MT32_PCM.ROM. After that, nothing changed. Then I changed rom_set=cm32l, after that, the oled states that the cm32l rom is selected. I can then press the rom button once to change to 1.07. After that, every button push is only "ROM set not avail". I would expect that I could cycle through the roms, but somehow, I'm not sure what mt32pi expects with its autodetection and button behavior.

Anyway, thanks for the very awesome project.

[dwhinham]

...shouldn't the control scheme be set to simple_buttons as default configuration? I soldered the buttons to the pcb and was surprised that they didn't do anything. When I changed it to simple_buttons, they started to work (somewhat).

Correct; I've just forgotten to add this to the page - I've added it now, thanks!

2. I'm wondering what the actual behavior of the rom button is.

Please read this page carefully (mainly the ROM scanning section) to learn how the ROM switching behaviour works: https://github.com/dwhinham/mt32-pi/wiki/MT-32-synthesis

It makes zero sense to have multiple versions of the 1.xx ROMs, because Munt's behaviour won't change, hence you only need one 1.xx control ROM, one 2.xx control ROM, and one CM-32L control ROM, as well as an MT-32 PCM rom and a CM-32L PCM ROM to get full functionality of the switcher.

The names are not considered when scanning ROMs, so renaming them will have no effect at all. ROMs are matched using their hash, which is like a fingerprint of the data.

If you have, e.g. 1.04 and 1.07, and mt32-pi happens to see 1.04 first, that one will be used for "old", and 1.07 will be ignored. Hence, you should only have one rom per "category".

---

Edit: I've just added some tables to the MT-32 synthesis wiki page to try and make it more obvious how the ROMs are classified.

[dwhinham]

I've just realised that if you don't have all 3 ROM sets present, you won't be able to switch between them using the button. E.g. if "new" is missing, you cant switch between "old" and "cm-32l" using the button. I'll fix this shortly.

[bzeiss]

Aaah, ok. Sorry, I kind of missed that mt-32-synthesis page. It explains a lot! :-) I guess it was bad luck that I stumbled over a problem that only happens with two roms versions :-)

[dwhinham]

No problem at all, thankyou for testing and posting! 🙂

It's been a while since I've tested without all of the ROMs present on my device so I've missed this scenario, and it's actually going to be a very common scenario because most people won't have the 2.x ROM. I'll make a new release tonight that takes care of it. 🙂

---

Edit: v0.8.3 is now available.