Wanted: another 12C for reverse-engineering (two-chip, non-diaper)

[brouhaha]

(11-16-2022 12:27 PM)mfleming Wrote:  Older 12C's were selling at throwaway prices a few years ago. What serial number range (and country) is appropriate?

I don't know about "throwaway prices", but there certainly are many on eBay that are fairly inexpensive. It's just hard to tell which ones might be the construction I need. I bought three for about $20 each, and while one turned out to be the right model, it also has a very flaky keyboard.

The serial range (year/week) that has the single-PCB two-chip construction might vary by manufacturing site, but I don't know that for sure. It's likely that USA production switched over before other sites. My general guess is that units made between late 1982 and 1988 (serial prefixes 22xx through 28xx) may be that construction.

Since Mark has generously offered to send me yet another 12C, this time S/N 2540, I can't really claim that I need any more units, though I also wouldn't turn them down if offered since sometimes in the experiments it has been helpful to have extra units.

At some time in the future, after I've made progress with the SST 12C, I'll want to obtain an SST 15C. The 15C is different than the other Voyagers in using (originally) two R2D2 chips. That meant that all of the 15Cs had three chips, until the SST was used, and then the 15C had two chips. I'll eventually want to experiment with one of those.