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hi out there,

tonight i heard primitive lofi squeking in my lab - so let me introduce you my Midibox AY 3 8912 adventure.

the Midibox AY 3 8912 is stuffed with a general instruments AY-3-8912 sound chip.

user interface (cs): a c64 keyboard (c64 keyborad 8x8 scan-matrix interface, thanks to TK and Bill !  :) ) and a 4x16 LCD

the sound is: lofi, rough, abstract (do you remember the arcade game 'moon patrol'?...  ;)  ;D )

here some AY 3 8912 background:



here some pictures (visual notes):



- lemonhorse

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Nice one man!!!!

To be a 'user project' we really should move the documentation to the midibox wiki (see the sticky thread in this forum). This is important because, unfortunately, offsite documentation is proven to be less persistent... What I mean is, they disappear :( (Yes, I know how long your site has been around, don't take it personally :) )

I'll leave this here for now anyway, I'll give you a hand moving to the wiki if you like? Just drop me a PM.

Great work though man! The download link on your page seems busted though :'( Can't wait to hear it!

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hi stryd_one!

midibox wiki: you're right - i will do - but i think my notes are too "freaky" at this stage  ;)

i would like to create more practical (user friendly) documentation...


i will release the firmware when the basic midi functions work (the midi implementation is rudimentary at the moment)

ay 3 8912 sound (mp3):

same here - i'll post some sound (mp3) when the basic functions work (midi implementation)

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for the response!

I implemented basic Midi functions today (Note On / Note Off).

Here is a little bit sound of the MB AY 3 8912 (midiboxay38912cha20080621.mp3)

My very first MB AY recording! - You'll hear Tone A (No Tone B, C or Noise).  Just a sign of life ;)

Unfortunately there is some crackling in the record - it's *NOT* the MB AY.

It's just an issue with my soundrecording device.

Best Regards,

- Lemonhorse



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Great work!

I must say, I'm so impressed with everyone pulling together all of these MIDIbox user projects for all the classic chip synths.  I had acquired some AY-3-8912s and POKEYs several years ago, but never had the time to do anything interesting with them.  Kudos, and I look forward to seeing the final project!  :D

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Software Update: mbay38912v001i.zip (experimental pre release :: 29.06.2008)

=> http://www.midibox.org/dokuwiki/midibox_ay_3_8912

* Enabled discrete TONE A B C / ADD NOISE A B C via MIDI CHANNEL 1 2 3

* Created a new MAIN MENU (to choose the 6 sub menus via c64 keyboard)

* Created a New MIDI CONFIG MENU for the MIDI CHANNEL of TONE A B C / NOISE A B C (not working yet)

still a lot do  ;)

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  • 2 weeks later...


Made some improvements @ TONE-A/B/C Note On/Off: enabled the "ENVELOPE MODE" (THE INTERNAL AY CHIP AMP CONTROL)

Now I'm playing around with the TUNE MENU. Sometimes I have to rewrite my own "newbie code" - it's my first asm coding project - I have a lot of fun, but I got to learn a lot as well...  ;)


The AY 3 8912 features Tone A B C out, so I created a small OP AMP MIXER BOARD with Eagle. Mike (PCB-Mike) will etch the board next time (AUDIO MIXER: 3 TONE CHANNELS [A/B/C] TO ONE AUDIO OUT) - then the next step is on my side: checking. After a successful checkup Mike will provide the board and I will upload the Eagle Data (board and circuit diagram) for everyone.

The AY 3 8912 module will be the next board to come.

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