Most custom chips have thousands to many millions of transistors in them, and big companies with state of art equipment struggled to make them in past... I don't think the time when we start creating our own CPUs and chipsets with homemade equipment is gonna happen anytime soon...

I saw this a while ago and it is really cool but it has a very long way to go.

FPGAs and CPLDs are still the way to go in my book... I can replicate a whole vintage system, hardware-accurate (with space to spare) in a medium-size FPGA for under $100.

stamasd wrote on 2019-12-27, 22:41:

FPGAs and CPLDs are still the way to go in my book... I can replicate a whole vintage system, hardware-accurate (with space to spare) in a medium-size FPGA for under $100.

Keep in mind that FPGA/CPLDs can only replicate digital chips, not mixed analog-digital chips. Some computers have ICs that are a mix of analog and digital components, like the ULA on ZX Spectrum and I guess SID on Commodore 64 (I guess most sound chips like OPL3, AY-3-8192) are mostly analog. Although a FPGA implementation is possible, that's an emulation that does not work 100% as the original thing.

OTOH, there are cheap FPGA based systems that can emulate entire systems, if you don't mind some inaccuracies (mostly related to keyboard reading and form size). I've got a ZX-Uno that is a bootable board with the size of a Raspberry Pi and can simulate most 8 bit computers/consoles... even it can store 9 cores (simulated computers) and you can choose any of them at boot time (but keep in mind that is built around a ZX Spectrum simulation, so core #1 MUST be the ZX Spectrum and that's the core that allows you to reprogram the board).

Tiido wrote on 2019-12-27, 22:29:

Most custom chips have thousands to many millions of transistors in them, and big companies with state of art equipment struggled to make them in past.

Yeah, this homemade IC has 6 transistors, a MOS 6502 has ~3000, a Intel 8086 10 times more... a long way to go, but I think something like the 6502 is reachable in the next decade.

Zup wrote on 2019-12-28, 09:05:

stamasd wrote on 2019-12-27, 22:41:

FPGAs and CPLDs are still the way to go in my book... I can replicate a whole vintage system, hardware-accurate (with space to spare) in a medium-size FPGA for under $100.

Keep in mind that FPGA/CPLDs can only replicate digital chips, not mixed analog-digital chips. Some computers have ICs that are a mix of analog and digital components, like the ULA on ZX Spectrum and I guess SID on Commodore 64 (I guess most sound chips like OPL3, AY-3-8192) are mostly analog. Although a FPGA implementation is possible, that's an emulation that does not work 100% as the original thing.

OTOH, there are cheap FPGA based systems that can emulate entire systems, if you don't mind some inaccuracies (mostly related to keyboard reading and form size). I've got a ZX-Uno that is a bootable board with the size of a Raspberry Pi and can simulate most 8 bit computers/consoles... even it can store 9 cores (simulated computers) and you can choose any of them at boot time (but keep in mind that is built around a ZX Spectrum simulation, so core #1 MUST be the ZX Spectrum and that's the core that allows you to reprogram the board).

I have the ZX-Uno too... nice system. I've also synthesized the ZX Spectrum on other FPGA boards, like the Pipistrello and the Altera DE0.
There are mixed-signal FPGAs too, which include analog blocks. Granted in most cases those are ADCs and DACs - but many if not most analog functions can be simulated with DSP slices, which most modern FPGAs have plenty of.

Zup wrote on 2019-12-28, 09:05:

(I guess most sound chips like OPL3, AY-3-8192) are mostly analog

OPL2 and OPL3 probably not - they use external DACs.

I think this project is more about changing people's mentality than make a complete foundry in your garage. Lately people is returning to a sort of new "middle age", strongly relying in "black boxes" and "magic" done by a few greedy companies here and there. People has to see there isn't any magic occurring anywhere, but a set of well understandable maths, physics and chemistry done in concrete steps to make the device to happen, and certainly isn't impossible to make a small scale (quantity and device complexity). I see in this project a way to encourage people to LEARN, instead to just buy stuff mindlessly, even if you never come to "make your own chip".

Louis Rossmann has an interesting talk about people's mentality in his Yt channel. I guess this project proves his point... And that's good. We need this sort of initiatives more than ever.

Zup wrote on 2019-12-28, 09:05:

Keep in mind that FPGA/CPLDs can only replicate digital chips, not mixed analog-digital chips. Some computers have ICs that are a mix of analog and digital components, like the ULA on ZX Spectrum and I guess SID on Commodore 64 (I guess most sound chips like OPL3, AY-3-8192) are mostly analog. Although a FPGA implementation is possible, that's an emulation that does not work 100% as the original thing.

OTOH, there are cheap FPGA based systems that can emulate entire systems, if you don't mind some inaccuracies (mostly related to keyboard reading and form size). I've got a ZX-Uno that is a bootable board with the size of a Raspberry Pi and can simulate most 8 bit computers/consoles... even it can store 9 cores (simulated computers) and you can choose any of them at boot time (but keep in mind that is built around a ZX Spectrum simulation, so core #1 MUST be the ZX Spectrum and that's the core that allows you to reprogram the board).

Has anyone looked at hybrid daughter cards that incorporate digital and analog sections for this kind of job? Unit production cost would be higher than genuine chips, but low startup costs would make it viable for low rate, hobbyist projects.