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TI-99/4A Readers may remember my attempts to do an in-console 32k upgrade, which failed with two separate techniques and I thought I'd killed the board.

Readers may also remember my recommendation to replace the console power switch as soon as one receives a console.

Turns out that I should have heeded my own advice. I finally got around to looking at the "dead" board. It powered up. Then it didn't. Then it did again, three times in a row, then refused to turn on.

Swapping the power switch with a DPDT rocker fixed that. I removed the 4116s while I was at it, because with a F18A they only consume power and generate heat.

So, closure. There's a rule in this house: either it works, or is in the process of being fixed, or it goes in the trash. I can now justify keeping this console to the wife. And this console has the known-good 16-bit 32k expansion, not the 8-bit possibly-misdocumented expansion, so I can swap it for the unexpanded console and get stuff done faster.

Upgrading a Super Snapshot V5.xx to 32k

Commodore So I've been in China for the past several weeks, trying to get ${EMPLOYER}'s crash production project back on track and mostly failing.

Having returned to Tokyo for a couple of days' rest, I'm not feeling up to doing anything heavy on the TI EE front. Feeling that I needed to do *something*, though, I decided to take a look at upgrading one of my Commodore bits-and-bobs.

Freezer cartridges were very popular in the Commodore ecosystem in the mid-nineties. A lot of people (mostly Europeans) swear by the Action Replay cartridge, but I always preferred the Super Snapshot. It was more geared towards the cracker than the Action Replay (which was geared towards the "infinite lives" gamer demographic).

I still have an original Super Snapshot v5.22 cartridge. I've left behind the original console, drives, and 100% of my software library over the years ... but somehow, that cartridge was always packed away somewhere in my seabag.

The Super Snapshot came with 8k (in the form of a 6264) on board, and was upgradeable (via returning it to the vendor) to 32k. I used the multimeter on a few traces, and determined that not only could it be field-upgraded, but it was built to use the 62256 as an upgrade.

Those who have been following this 'blog have probably figured out that I have roughly a billion 62256s lying around as part of my TI HRD+ experiments. So I fired up the soldering iron, unrolled the desoldering braid, and had at it.

Pro tip: the original manufacturer didn't clean up the left-over flux from the original FATP process, so it's best just to clip the 6264 off of the board, pull the leftover pins, and clean up the holes with the braid. Scrub well with isopropyl alcohol, let it dry, and put a 28-pin socket in.

There's an unsoldered jumper block right next to the SRAM chip marked J1. It's hard-wired for a 6264. Cut the trace between position 2 and position 3 of the jumper block, put a wire between position 1 and position 2, and emplace a 62256. I recommend the Alliance CMOS 62C256, but whatever is available is fine.

If you're wondering what J2 on the board does, it's for the C128 kill switch. If you have a C128 and you want to keep it from going into C64 mode when the cartridge is plugged in, cut the trace between the poles on J2 and use a switch to bridge the now-isolated poles.

So there you go ... if you have an original SS, this is how you upgrade it to 32k. Hope this helps someone.