Author Topic: Replacement Bally -35 MPU PCB's - Unpopulated!  (Read 1508 times)

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Re: Replacement Bally -35 MPU PCB's - Unpopulated!
« on: December 17, 2010, 10:35:24 AM »
Well we are in the final labelling and double checking stages of the Bally -35 MPU board. Another day or so and it should be ready for the circuit board house to make the first batch. Some might note we have 'beefed' up the tracks a little and we have used some artistic licence to make several small improvements over the originals. One of these mods can be seen in the last picture where we have retained the original (dumb?) mounting holes for the transistors on the board so that people who wish to assemble it as close to original as possible are able to - but we have added more modern (and sensible) pad layout for these transistors.

After that we will have to assemble and test a few to confirm all is OK. This will take another month and then the writing of the assembly manual probably a further month. Here are some current shots of the artwork (still with legends to mark and move about).

Bottom view


Top view


Closeup near the EPROMs


Sensible - added transistor mounting holes
Replacement Pinball PCBs that remain faithful to the originals