TM500-series extender ?



Does anybody know where I can find a flexible TM500-series extender for a price better than the original ones ?




I made one a couple of years back using a JAMMA extension. It’s very easy.
Mine didn’t work at first because I had made a few mistakes, but people here helped, and now it works like a charm. It’s been very reliable so far. All you have to do is rewire it, and cut a slot.
Here’s a link to the one similar to the one I used. Although 2 came for that price back then.

If you Google it, you can also find a tutorial online. I don’t remember by whom. Maybe someone else can point you in the right direction.

Hope this helps.

Dave Peterson

A solution is to use a JAMMA extender.

JAMMA is an arcade game console standard:
Note that the wiki page also identifies the Tektronix as an adopter of the edge connector.

Search for "JAMMA connector spec" and you'll find many descriptions of the pins.

I asked the same question last year, and folks here helped me out. See the thread associated with this message:
Note that it includes a link to a photo album with a few pics of what I built.

I was recently asked if this connector would be a good source:
I think it is, and is probably easier to modify into a TM500 extender. I don't think any rewiring is called for. I needed two for a two slot plug-in, so I purchased a less populated connector for less and had to rewire it. It shows as no longer available, and suggests what I think is the same harness:
If the link doesn't work, just search for JAMMA Extender Harness
These shouldn't need rewiring, but see my notes below. I suspect some modification needs to be made to the board edge side of the harness.

Another member of the group asked me about this recently, and here are some observations I provided. I'll just paste as it's all the further info I'd share:

In the JAMMA spec pins 1&2, 3&4, and 27&28 are going to the same thing (Gnd, +5v, and Gnd respectively), and on the edge board that I acquired pins 1&2 and 3&4 were shorted together. They were a single metallization on each side of the board. I had to Dremel a channel between them.

The example I purchased had a jumper between two connectors on the connector side. I don't recall which pins, but perhaps 1 and 14 (Gnd and Video Gnd?). Check for any such jumpers in the wire loom. I suspect they'd be obvious though, and it doesn't look like it from the pictures.

The black connector, and the one in your listing looks identical to what I bought, is _very_ flimsy. The plastic is almost like polystyrene - very easily melted with too much heat on a connector. I get too fussy with my soldering and didn't realize I was melting it. Luckily some JB Weld saved it for me. And the connectors themselves are also very cheap, thin, flimsy affairs. But then you shouldn't need to be soldering at all if they are all truly 1-to-1 connected to the edge connector. Certainly an advantage of this design. Just be careful with them. They are not as robust as original Tek equipment.

The connector is rather "free" in end-to-end play on the connector where it attaches to your plug-in. I _think_ the end play limit is just shy of shorting one pin to the adjacent. But I glued in a small piece of model sprue to remove some of this play.

Otherwise mine have worked very well. I take care when using them as they are not keyed on the connector side. They are infrequently used, so I'm fine always taking my time making sure I'm plugging them in right.

This is just one solution. You can also buy more robust connectors, wire, and PCB board edges to DIY. Or set an eBay watch for the Tektronix originals. They are more robust and safer than these JAMMA harnesses.


Richard Peterson

Dave beat me to it. . . . I'll be ordering the one he linked when I pull my DC501 for repairs.


Hello Dave,

Thank you so much for the detailed and informative answer !

I will carefully take that into consideration in order to get the extender.

Best regards,



Hello Stephen,

Thanks for the provided information, really helpful.

Best regards,



Get a TM502A, usually under $100 on EBAY shipping included. Remove the outer cover. What you are left with is a box about 6" by 8" containing the power supply with the two slot connectors. Put it on the bench and attach the plug in you are debugging. The box has the alignment guides so hard to get it aligned wrong.. Use slot 1 or slot 2 as needed depending on the orientation you need for your debugging. It also works well for two slot plug ins.


Michael W. Lynch

I use a TM501 in much the same way. I have one TM501 that I have Cut down the side rails to allow improved access to the entire circuit board of the DUT.

Michael Lynch
Dardanelle, AR


TM502, TM501... you can even use a TM503!!

A bit more bulky, of course, but no need to cut down anything. I often use the rails to stabilize my hands when probing components.



I agree 100%, a TM502A without the cover IS the perfect fix for doing TM500 module repairs, it's what I use
when I have to do any serious module work. I also have extenders for quick adjustments,
so some choices are very useful.

I do have a couple of the Tek frame mating connectors left if anybody needs one for an extender.

all the best,
walter (walter2 -at-
sphere research corp.