So i've been looking at creating another new board for system 80B games. This time i'm looking at creating a new sound board which will work across the 80B games. It will be compatible with MA-766 and MA-866 series boards and variations thereof.
Been drawing up some schematics before getting some protos made to mess/test with. Looked over loads of schematics from various games and completed the first run of my schematic which will allow the board to work in games meant for the 766 and all revs of the 866 board. There are dip switches to enabled/disable certain sections which are specific to the different board revisions. The main difference is to do with the speech generation circuit. The speech generation for games using the first rev of the 866 board like robo-war and tx sector certainly is an interesting design and some of the games using the 766 board where there was a dedicated speech chip, didn't even use it! Robo-war managed to create that transformers like voice with lots of low pass filtering.
As before with the cpu board i will be looking at improving the design and including similar updates, such as:
- Decent ground anchors
- Test point pads for common signals and voltages
- Leds for common signals and voltages
- Reduced component count
- Plate through design, socketed ics
- Kit option
Also, after looking at a good few system 3 manuals i believe this board will work here to so the full range of games able to benefit will be much higher than originally thought. Again it looks like gottlieb carried on using the 866 board for effects and updated the aux sound driver to improve the speech generation circuit again. Music gen was split across the 2 just like in later 80b games.
I'm interested to hear what people think, who would be interested in buying this board and whether a kickstarter type approach may be a good way to run this project?
Will be also keeping dev progress updated on my blog at http://blog.mypinballs.com and on www.mypinballs.co.uk