Wednesday April 23, 2014

Techdose Blog



Gottlieb System 1 NVRAM Adapter (for 5101 RAM)
Here's one of the prototypes I had made up in January, a Gottlieb System 1 Pinball NVRAM Adapter. Still in the testing phase on this one, more info over at Pinitech. I don't expect it to be a huge seller but since there does not currently exist any NVRAM or 5101 adapters for the Gottlieb System 1 I figured why not throw it in with some other prototype designs I was having made.

As for how well this might sell -- I'm thinking it's going to be affected by a narrow market for this type of product. First, Gottlieb System 1 pinball machines just aren't as popular as some of the Bally/Williams machines from the same era. Second, if someone has an issue with their MPU they are often replacing it with a brand new Pascal or NiWumph System 1 MPU that has additional features and NVRAM already on the board. Third, even if someone wanted to keep the original board and upgrade to NVRAM, the original 5101 RAM is soldered to the board. So the market starts shrinking with all these factors not to mention the already niche market of pinball machines. I could be wrong, but I'd think most people with working boards aren't going to want to touch what's not broken and the percentage of people with the right equipment and skill to desolder the RAM and purchase an NVRAM adapter would be fairly small. That still didn't deter me from creating this prototype to work toward the goal of a functional adapter for System 1 machines though =)

Posted Feb 26th, 2014 8:31 AM by AceBHound
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Back Into Design
Over the last month I had a chance to get back into "design mode" and work on some new prototype circuit boards. It feels good. I love the creativity that comes with designing anything and the reward is always in the satisfaction of having built something that works and actually seeing it work as you envisioned. Anyway, a bunch of new prototypes are coming in over the next few weeks and I'll probably be sending a few more off before I get back into some house projects again. A few of them will get made into products I'll sell over at Pinitech and some are for my own use when repairing machines. If I think I can build it relatively quick and it's going to save me a bunch of time, I'm going to build it. I also plan to get into some microcontroller programming sometime this year -- I've had a couple of development kits sitting around for a few years and I'm finally at a point I think I could benefit from the use of a microcontroller in some designs. Should be an interesting year.

Posted Feb 5th, 2014 7:54 AM by AceBHound
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New high score, is that bad? What does that mean? Did I break it?
Over this weekend I decided to work on a little 5101 RAM adapter for my GQ-4X programmer. The objective was to have yet another way to test 5101 RAM adapters I'm building and also be able to read the data off of these ICs. I settled on the final goal being able to read off one of my budget 5101 RAM adapters that was in a Bally Mr & Ms Pac-man MPU. I'd been testing battery life on the adapter so have left the high score as "1799920" and every month or had been checking that the high score is still there and the 3v coin cell battery was still alive.

The Goal: Read Bally game data that was saved to 5101 RAM adapter via GQ-4X programmer. Copy data to a new RAM and install into Bally MPU to verify high score was copied.

It took a bit longer than I expected, but I was able to hack around with an old prototype board and create a functioning adapter. Ultimately the GQ-4X software/hardware was a bit flaky at times and causing me issues, so it took me a while to catch onto that. In the end I was able to copy 5101 saved data to a new RAM and when placed into the mpu board saw my same high score "1799920".

So then I took it a step further and tried looking for the high score in the data, with the intent of changing it. The Bally/Stern mpus only store a nibble (half a byte) to the RAM since it's a 4-bit device, so when searching for where the high score was I knew it would be scattered across several bytes. I had also assumed it would be stored in HEX since it would save a few bytes, but as it turns out the score was stored in its decimal format, tho backwards "0299971". Of course I had to set a new high score after finding it, so I changed it to "5432171" and wrote the data to a RAM chip. Once installed in an MPU my new "fake" high score displayed as "1712345". Cool.

Not that any of this is extremely monumental but it should help further some of the projects I've been working on where it would really help to view what's on the RAM or be able to program default values to the RAM before installing it in a machine.

Posted Jan 13th, 2014 6:51 AM by AceBHound
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December 2013 Update
Seasons Greetings! Hard to believe it's December already, but I've had a busy 2nd half of the year working on house projects and not much time to devote to posting anything here.

I don't think I ever mentioned it but the 6264 NVRAM Adapters I sell now have a custom PCB board made up for them. Nothing has changed and they function the same as they had previously but now I can control the design and quality of the boards, plus it has the nifty "PINITECH.COM" text on it :)

Recently I've been working with several Skee-ball alleys. There's a Model E CPU (Model 78 machine, ie. built in 1978) that had non-working electronics. This early model CPU uses mostly 74xx series logic chips since it was built back when CPU chips were very expensive and it was cheaper to build electronics using logic gates. Pretty fascinating actually and at some point I'll hopefully get some more info posted on these earlier machines. The only non-standard IC on the board is what's referred to as a "timer chip" that looks like it's something custom that Deltronic Labs Inc. created. Have not been able to find any info on this at all. Anyway, turns out the cpu unit had the 5v voltage regulator go bad in it.. no 5v to power the electronics. Once replaced all was well.

I've been selling some of my custom pinball tester boards on eBay and my Pinitech website. Have been kept busy in my couple hours of free time staying ahead of orders and shipping them out, trying to build up some extra inventory so I'm not creating the boards on-demand as I get the orders. Overall it's worked out pretty well.. I'm happy recouping costs of prototyping and materials.. anything beyond that is a bonus.

More updates and new projects to come in the new year! Merry Christmas!

Posted Dec 17th, 2013 7:04 AM by AceBHound
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Bally/Stern Bench Setup
Here's a bench setup with some of the diagnostic equipment I've been building for early Bally/Stern MPU's. At the top left is the second version of the bench display board that plugs directly into the MPU. At the top right is a 40 switch tester for the playfield switch matrix. At the bottom right is a small cabinet switch / self test switch tester. All of these together allow you to test many functions of the MPU board out at the bench (when repairing or checking boards for functionality).

I'll post some more on these boards in the future and they'll be available on eBay and Pinitech.com soon for purchase. Product pages for the Bally/Stern Playfield Switch Tester and also the new version of the bench LED display are up on Pinitech. Some of the items will be available in kit or as bare boards as well as fully assembled.

Posted Jun 9th, 2013 12:28 PM by AceBHound
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Previous Topics

05-11-2013
More Boards On The Way

05-11-2013
Bally/Stern 5101 Budget RAM Adapter

04-18-2013
Gottlieb NVRAM

04-04-2013
Classic Bally / Stern Pinball - Cabinet Switch Testing Tool (connects to MPU)

03-21-2013
Announcing: Bally/Stern Bench LED Display

03-18-2013
Neoloch's Budget Memory Tester (5101, 6264 & soon more)


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