On 10/16/2021 at 10:50 AM, BruceMcF said:
If the next step up in that FPGA family has enough Block RAM to provide the 40KB in Low RAM as well as the PCM buffer and rowbuffers, I could see an X8 style system on the X16 memory map, with 4 High RAM pages, 2 "ROM" blocks and 64K Video RAM in the 1Mbit SPRAM, without the additional BOM & build cost of an external RAM. If the Vera FPGA could support a 65C02 core, perhaps the next step up could support a 6522 VIA core to support standard User Port.
All, mind, uninformed speculation (which from the abundant amount of it available throughout the internet is surely the most fun kind to engage in!).
I’ve been looking into the Lattice FPGA’s and I think the best step is an 8K type. I think the ICE40HX8K-CB132 is probably a good candidate that will have enough room for a full X-16 FPGA. I dunno if It’s going to require an external RAM chip to handle the X16 banking. I found an introductory course on FPGA’s to familiarize my self with this tech:
http://www.ee.ic.ac.uk/pcheung/teaching/ee2_digital/