For the technically interested, I'd like to point to this article: "Surface finish on PCBs and why it matters for reproduction carts" (link).
Gold plated edge connectors are, without doubt, the best choice. The poster in the article points out, though, that a high number of insertions with HASL finish foremostly expose the copper below the tin, which then leads to corrosion on the edge connector fingers.
The conclusion reads:
So - tfw8b and Misfit would be well advised to take that recommendation to heart, especially with such a high-profile product. No one is free from errors though, and supposedly it's the first time it has been pointed out to the manufactorer, that he shouldn't miss out on this little bit of extra cost. However, eslapion made them aware of this issue in the possibly most undiplomatic way one can think of. As you can read in the original thread, and following the responses of Misfit in this thread here, the cartridge has been made 'out of stock', i.e. for all intents and purposes discontinued!HASL finish PCBs are absolutely not meant to be used as game cartridges. They do however have their place, especially in unexposed PCBs where mechanical connections to the PCB are not required. But, in every case, always ensure the game cartridges you buy, wherever you buy them, are finished with Hard Gold. At the very minimum, refuse to purchase any game cartridges which do not have a gold-coloured surface finish. If ambiguous, ask the seller what finish the PCB has – an informed seller will know and will be happy to tell you!
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As long as the cartridges have not been assembled, and this probably also depends on the number of PCBs of this first batch, it should be possible to add a hard gold plating on the edge connecter in an after-processing step. That would limit the possible loss.
Misfit, I strongly hope that what you wrote is not the last word in this matter. Your engagement in the VIC-20 community would be sorely missed.
