I picked up a few during that run, as I remembered picking one up from Radio Shack in the 80s and having fun with it. A really delightful chip to explore, you can get so much out of it just messing around with RC circuits for the various timings. The original docs are quite opaque; just a few minutes with this new article is really revealing.
I've wondered that, too! Even considering the low complexity, that's a couple of 100k investment, at least.
Can anyone here approximate the cost to re-produce this chip ten years ago? I mean, it's not very complex, but it is analog and it couldn't have been cheap. Maybe someone had to find a use for an old machine that had nothing to do anymore? That could explain it.
They most likely found a source for NOS (new old stock) chips. I find it highly unlikely that they started another run.
Considering the age of the chip, the masks are probably not even available in a digital format and the fab that made it had been shut down a long time ago. Recreating these processes is a massive undertaking that takes a lot of manpower.
