Sunday April 30, 2017


February 2013 Update
  Posted by: AceBHound on Feb 18th, 2013 9:09 PM
The prototype boards I ordered last month all came in and I've been testing a few of them in machines. One of the prototypes I've been fooling around with is a 5101 adapter for early Bally/Stern/Williams machines. I've actually had quite a few 5101 prototypes -- a cheaper version that used regular battery-backed RAM, a version that used a DIP part, a version that allowed use of several SOIP surface-mount RAM parts, another more condensed battery-backed RAM design.. and there have been others as well. I think I've finally settled on a few of the designs and am testing them in some machines currently. One of these is actually *slightly* based off the 6116 adapter I had wired up long ago here -- http://www.techdose.com/projects/6116-to-5101-RAM-Adapter-for-Stern-MPU100/361/page1.html

I got hung up on building memory adapters for pinball machines for several reasons. Most of the MPU board repairs I've had to make have been due to battery corrosion. Batteries are bad, mmkay? I also hate changing batteries.. sure it's only once a year but if you have more than a handful of pinball machines it's just annoying. I was also tired of bad memory causing me to spend HOURS trying to track down odd issues like bad scoring, digits not lighting and random game behavior. I spent literally *days* with a Stern Hot Hand pinball machine that was acting really haywire until I finally swapped out the 5101 memory with a different RAM. Why? Who has a large stock of a $5-10 RAM chip? Some people do I'm sure, but after that whole experience I started appreciating the ability to have good RAM to swap out in a pinch to rule out bad memory. So, that's why I went on to build some memory adapters with a vengeance.

Another prototype I had made up last year was a Gottlieb Game PROM adapter for Gottlieb System 1 boards (pictured). Again, a smaller simpler adapter board that solved an issue for me since I had a handful of Gottlieb System 1 pinball machines missing their game PROMs. Allows you to replace the obsolete Z23 PROM (contains game code) with a readily available 2716 eprom. It worked out extremely well and paid for itself in helping to fix up some machines of my own. If anyone's interested I do have a few extras I'll sell for $11 + shipping. You need to supply your own 2716 eprom and also find the game code (2716 binary) but nothing a quick Google search can't solve.

There's other ideas in the works, lots of materials ordered to make products. Just need to figure out how to slow the clock down and do the work of 2-3 people :)

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