I've found an old soundcard with the OPL3 sound chip from Yamaha (YM262M) and it's associated D/A converter, and everything is laid out, ready to get started at!
For those who is currious and want to see/hear it, visit:
http://www.ucapps.de/midibox_fm.html
When this project is done, I've decided to get myself involved in designing another FM synth for the MIDI Box platform... the good old YM2151 that was used in many arcade machines (marble madness and outrun to name a few)... it's a really nice and warm sounding little devil of a soundchip, and the system will be focused on unison use of it's 8 voices in a very userfriendly manner (for bass and leads)... I have downloaded the datasheets and stuff, and ahead waits the challenge; the challenge of electronics design (I'm a complete noob!
), and hundreds of PIC RISC assembly code lines... aaaahh! it's going to be like in the good ol' days... full hardware control, memory space limits, optimizations and stuff... ol' coding "ticks" have started to show themselves again in me! 
I'll post sound examples as the project goes ahead, for those currious.
... I miscalculated when purchasing EEPROM RAM chips... needed eight, thought I had 4, so recently bought 4 extra just to realize that it was THREE I had at home... damned! 
... and for some reason, a tiny little capacitor was also missing... so now I have to go ordering stuff again 
), we got it working... and oh dear, oh dear! ... this thing can be EVIL!!! 
... it's DIRTY! and have a life of it's own, almost like SID...
