|Neoloch's Budget Memory Tester (5101, 6264 & soon more)
|Posted by: AceBHound on Mar 18th, 2013 7:25 PM
|Last year I stumbled across a Youtube video of a 6264 RAM Chip Tester by David Hoffman at NeoLoch, LLC. I think I was just looking for a generic/budget RAM tester at the time. It used a PIC to write data to the memory & then verify via a read operation. Unfortunately it was just a prototype breadboard design & although the schematic/firmware was available, it seemed a bit much of a project just to be able to test 6264 RAM. I really wanted to be able to test several types of memory used in pinball machines -- like 5101, 6116, 6264, 6810.
Earlier this month while once again searching for a memory tester I found out that toward the end of last year someone in the pinball community had asked David if he could adapt his design to also verify 5101 RAM chips. Which then lead to David actually creating a PCB board for the design. Better still, since then David has made a few other neat modifications to the design so firmware updates could allow for other memory to be supported in the future. Green and Red LEDs indicate memory address ranges that pass or fail.
Pictured is the fully assembled adapter. I had many of the components myself so I decided to just purchase the bare boards & build a few of these. Figure I'll use one for testing chips and possibly leverage the hardware setup for some other uses.
It works great! Right now it can only test 5101 & 6264 RAM, but David will be adding support 6810 and a few other types of arcade RAM. Hopefully the 6116 RAM is also added. This will make a pretty complete RAM tester for pinball/arcade games. If you've never had to diagnose issues caused by bad RAM, then consider yourself lucky. This kind of tester is worth its weight in gold when you suspect faulty memory -- which can cause all sorts of weird issues in devices. In pinball machines scoring can get all messed up, digits missing or scores increasing by very odd values, high scores and settings could be affected, incorrect lamps/coils activating. The sky's the limit when faulty memory can make it past self-tests on these machines & bad data is being used. So for anyone that fixes a lot of pinball arcade games, pick one up for under $30 assembled from NeoLoch.com or you can even buy as a kit or bare circuit board if you don't mind a small project and want to save a few bucks! Great work David!
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