SOPCM1 Revisits

First of all, Happy 4th of July for the USA and anyone else who wishes to celebrate!

As a follow-up to my last post, I spent some time recently finally getting around to revisiting ROM archival, this time, of Roland’s SO-PCM1 and SO-JD80 cards.

As you can see with this image, the process has not been particularly trivial. The reason for all the wires is because of the physical format of the cards on the left. Not much seems to be known about it, which is understandable since it even predated PCMCIA, but what is known, judging from service manuals for synthesizers that can use them such as my JD-990, is that Roland actually did NOT create the card form factor: the associated connector in said service manuals instead point to JAE Electronics (the connector for them is an obscure JC-20-C40PC-LT2-A1H). To make things further interesting, deep enough research found a PDF for some other variations of the brand’s card factors, though none are compatible (most similar is a 45-pin variant known as JC20-C45P-LT2-A1).

Needless to say, without overly extensive electrical knowledge or the courage to risk permanently damaging my synthesizers via poor disassembly, the only way to have an easy chance of reading these cleanly without a supported synthesizer is via wiring into an EPROM programmer, of all things. Fortunately, the service manual for the 990 is generous enough to reveal the pinout for the connector, so it was just a matter of making sure the wires connected to the correct ends without crossing others.

One challenge that doesn’t go without saying is that two of the SO-PCM1 cards supported a whopping 2 MB of data (all other SO-PCM1 cards and the entire SO-J80 range only use 1MB), whereas the pictured configuration is the equivalent of a mere 1MB DIP EPROM, so some crossing of the ground and current pins had to be done to get one full read for those two volumes, but otherwise, the results paid off.

It may seem strange that I’m trying to preserve data from old gear as a third party, but if there’s one thing one of Brad Fiedel’s Fairlight CMI3’s has taught all of us earlier the past year, it’s that anything can happen that will cause a piece of history to be lost forever…so if you care about whatever you have, back up what you can while you can, especially if it’s decades old or more.