unexpectedbowtie
Offline
Glasgow, Scotland.

Hello!

I dug out my old C64 and MSSIAH cart combo and got it rigged up with an external monitor, with the intention to play it using the mono synth program. Everything is working great, and the diagnostic tests show that the SID chip is fine - loud sounds coming out in response. The one problem is that when I get into Mono Synth and set it up to be played with the C64 keyboard, there's no audio output.

Here's what I'm doing in Mono Synth:

1. Go to Settings and set the MIDI option to 'C64 keyboard'.
2. Set the Synth to MIDI mode so the screen goes blank.
3. Play the keys with different Patches loaded.

I can hear some sort of change in the audio output - in that there's a very very quiet click or whirr at different frequencies depending on the patch, but there's no other output. No big SID sound like I'm getting from the diagnostics.

Am I doing something stupid? Probably... It's hard to read the dials so it could be that I'm missing something really obvious, but I'd have expected some sort of more audible output with at least one of the default patches.

Help :'(

dustfilledhobo
Offline
Salt Lake City, UT, USA

When reading your initial description I thought it was a SID with a dead primary voice, but I see you're able to get sound out of the diagnostics test.  so, I was obviously wrong. 

Your steps seem correct to me.  This might be a long shot, but have you tried cleaning the cart slot of the C64 and the pins on the MSSIAH cart?

Anyway, good luck!

unexpectedbowtie
Offline
Glasgow, Scotland.
dustfilledhobo wrote:

When reading your initial description I thought it was a SID with a dead primary voice, but I see you're able to get sound out of the diagnostics test.  so, I was obviously wrong. 

Your steps seem correct to me.  This might be a long shot, but have you tried cleaning the cart slot of the C64 and the pins on the MSSIAH cart?

Anyway, good luck!

Yeah, it's pretty strange. I haven't given it a good thorough cleaning, so it could be that dust is interfering somehow. I'll try that out today.

akira^8GB
Offline
New York City

Mono starts with an "init" patch, meaning none of the SID sound registers are set. Patches may not be loading or something. It could also be a filter problem.
MSSIAH's SID "test" is far from complete, just because you get a beep out of it doesn't mean you get sound out of the SID with every waveform and filter combination.
It has nothing to do with the cartridge, if you had a problem with the contacts, the software wouldn't load at all.

Last edited by akira^8GB (Jan 29, 2016 2:53 pm)

unexpectedbowtie
Offline
Glasgow, Scotland.
akira^8GB wrote:

Mono starts with an "init" patch, meaning none of the SID sound registers are set. Patches may not be loading or something. It could also be a filter problem.

Hey,

Thanks! Any particular suggestions on what I can try to remedy/troubleshoot the problem?

akira^8GB
Offline
New York City

This is the only SID diagnostic tool you should ever use:
http://ploguechipsounds.blogspot.com/20 … hmark.html

unexpectedbowtie
Offline
Glasgow, Scotland.
akira^8GB wrote:

This is the only SID diagnostic tool you should ever use:
http://ploguechipsounds.blogspot.com/20 … hmark.html


I'll have a bash at that, thanks.

With regards to these bits:

Mono starts with an "init" patch, meaning none of the SID sound registers are set. Patches may not be loading or something

Does that mean that re-loading the patches could help? I'm not sure how to set the sound registers.

Thanks a lot.

unexpectedbowtie
Offline
Glasgow, Scotland.

Got it working by opening up the demo patches, which seemed to kickstart things fine!