Midway Space Invaders has me stumped

FIXED!!

I ordered a SN75365 as it was the cheapest part I could find. The 3245's were pretty spenny. Had it shipped from France and in total it cost $7. I have temporarily wired it up using jumper leads as per the instructions.

Surprise surprise, the game fired up right away. The RAM had survived the destruction of the 3245...Thank goodness. I was 80% sure I'd put 12V into the RAM where I shouldn't have.

And even better, now I don't get a RAM error @ #7. So I guess the 3245 was dying anyway, and in some ways it was fortuitous that I killed what remained of the dying chip.
Serendipity!

Anyway, just wanted to thank everyone who chimed in with advice, especially Stoog.

Next, I have to fix a few dead sounds, but hopefully that should be relatively easy.

Phil
 

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Haven't gotten around to fixing the sounds yet, but thought I'd share the little adaptor board I made for the SN75365. So no mods to the mother board what so ever.
 

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Did a bunch of probing last night with my scope and identified 2 LM3900's and the CD4006 as suspect. Replaced all three this morning and now I have all my missing sounds back. 3 for 3 ain't bad!!!

The only remaining issue is the length of the missile sound. It's way too long. Does anyone know what part controls the length of this sound?

Much thanks

Philip
 
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