FM Synthesis (YM2151)

[Thrashbarg]

Hi,

I'm back at building synthesizers again. This one is based around the Yamaha YM2151 FM synth I pulled from a dead arcade board.

Some demos

http://www.youtube.com/watch?v=qtGIF5vdcEg
http://www.youtube.com/watch?v=etBmrJAaA0o
http://www.youtube.com/watch?v=itcHj46oaK4 <-- I'm particularly pleased with this one

There's no video in these, just a picture of the YM2151 IC from Wikipedia. The last time I tried making FM synth with this chip was in my 8080 computer and I had no idea how to do it properly, so it sounded awful. I found this website (Japanese) which has a mountain of patches for these synths.

http://park14.wakwak.com/~valsound/fm_lib.html

Which make it sound a lot better

Also the thing has died on me again... Back to beeping out bad connections. Here's a pic of it too.

http://kaput.homeunix.org/~thrashbarg/6510.jpg

Sorry about the bad upload speed

 

[Brendan]

Very nice! I truly enjoyed listening to these this evening. Excellent choice of composers and pieces, too, IMHO. Thanks for sharing.

Can you explain more in general about how you're driving this? It looks like you effectively have a small single-board computer there. Is that right?

 

[Thrashbarg]

Very nice! I truly enjoyed listening to these this evening. Excellent choice of composers and pieces, too, IMHO. Thanks for sharing.

Can you explain more in general about how you're driving this? It looks like you effectively have a small single-board computer there. Is that right?

Yes, it's a basic 6510 (6502 core) computer, 8kB ROM and RAM, 6850 ACIA for the MIDI and an 128x64 pixel backlit LCD display which I sill need to get running so I can program the patches.

I'll draw up a circuit in a bit if you want. It's pretty generic.

 

[carlsson]

Keep up the good work! I might be slightly interested in a schematic too.

 

[Thrashbarg]

Here's another one. http://www.youtube.com/watch?v=7WwNtO9YXww

The 6510 based synth fell over so I rebuilt it with a Z80. It was MUCH more difficult to program. I'm definitely a 6502 guy. A friend was happy though, he's a Z80 guy

Circuit diagram still coming... It'll be of the the Z80 version. I want to get the keypad interface working first.

 

[carlsson]

Perhaps the people building Lynchaj's Z80 single board computer could be interested in a sound chip add-on, as I suppose that project doesn't have one?