On 12/25/2021 at 5:23 PM, Ed Minchau said:
Look at it this way: in the 1980s, Commodore had their own chip fabrication plant. That's how they produced things like the VIC chip and VIA chips for audio and video for the VIC-20.
The VERA daughterboard is definitely something Commodore could have done in the 80s, though it would be a much bigger board. And of course we're already using 512kb RAM ICs, which for Commodore would have been an enormous PCB flooded with 2kb RAM chips. Point is, Commodore could have produced VERA, and all the rest of the Commander X16. Their only real obstacle would be the RAM, and SD storage was just a dream back then. An FPGA like VERA would have been a factory-programmed gate array rather than field programmable, or several such ICs.
The ATtiny used for Reset and power on wouldn't have been present on Commodores because of the external power box feeding a single voltage to the computer, but if they had needed something like that it would have probably been done with a special-purpose chip that they fabricated themselves as well. It isn't doing a whole bunch of 16 bit or higher math, and might have been implemented with a bunch of TTL logic gates instead. If they were putting 2Mb of banked RAM in a machine, the case would already be big and would contain lots of PCBs, so what's one more?
Then again, there are a few "crochet hook" ideas that in hindsight, should have been dope slap obvious, but back in the day no one ever thought of.
Take stacked RAM. The idea of
stacking four to eight DRAM dies using through-silicon vias, plus DRAM refresh logic and possibly a DMA and/or MMU on a package no larger than a then-typical DIP should have been blindingly obvious, but it didn't happen. Done right, a 64K Pseudo-SRAM version should have drawn no more power and/or generated no more heat than an 8K SRAM on the same package, and massively reduced the chip count of, say, the Commodore 64 and subsequent follow-up motherboards.
Unity Semiconductor, creators of CMOx Flash, was poised to turn the nonvolatile RAM market upside-down, but then they were bought out by Rambus, which scared all possible potential licensees off, due to Rambus' reputation as sharks. They had white papers that it could have been produced on conventional CMOS tools, and tested the concept at a five micron node.