Repo Man11 wrote on 2021-01-22, 02:47:

Too bad there was never a Socket 462 to Socket 7 adapter. And I will always wonder if AMD ever had any engineering samples of Socket 7 CPUs using Athlon tech.

Oh that would be cool. I suspect they may be too much power draw for typical socket 7 boards though? Athalons got more toasty than the k6. What do you think?

It would be pretty cool to have an FPGA drop in CPU for socket 7 or slot 1 that could be configured on the fly for different speed profiles. I am not sure how practical that would be given the expense of an FPGA and the limitations of HDL (I think the FPGAs you see in projects like the mister have a maximum theoretical clock speed of like 200mhz or something).

A few talented engineers could make a brand new, essentially perfect retro computer with enough time and money. It will never happen, but it's fun to think about.

mothergoose729 wrote on 2021-01-22, 07:08:

It would be pretty cool to have an FPGA drop in CPU for socket 7 or slot 1 that could be configured on the fly for different speed profiles.

For CPUs beyond slow 486sx FPGA is a no no, at least in "budget" models who power things like the MiSTER. An extra problem with Budget models, is that them waste silicon space and element count in ARM or PPC cores you will never use for a project like an FPGA based x86 CPU. To get in the levels of the Celeron-400MHz mendocino CPU, you would require some super expensive (and probably only available to certain markets), FPGA-only (with no core shit wasting silicon space/element count) chip like the Virtex or Stratix families... And even then, you would only go as far as Celeron Mendocino/K6-2s and that's probably the limit with the technology we have now. Totally not worth since you can get these CPUs as ASICs for pennies.

Now, a middle range FPGA-only chip, like middle-high line Cyclone's or Spartan's would be nice toys to attempt to make your own Pentium/K6 chipset... probably a 440lx if you push them far enough. You would be closer to something affordable to work your VHDL core code with, but still is something too expensive for many.

hyoenmadan wrote on 2021-01-22, 18:34:

mothergoose729 wrote on 2021-01-22, 07:08:

It would be pretty cool to have an FPGA drop in CPU for socket 7 or slot 1 that could be configured on the fly for different speed profiles.

For CPUs beyond slow 486sx FPGA is a no no, at least in "budget" models who power things like the MiSTER. An extra problem with Budget models, is that them waste silicon space and element count in ARM or PPC cores you will never use for a project like an FPGA based x86 CPU. To get in the levels of the Celeron-400MHz mendocino CPU, you would require some super expensive (and probably only available to certain markets), FPGA-only (with no core shit wasting silicon space/element count) chip like the Virtex or Stratix families... And even then, you would only go as far as Celeron Mendocino/K6-2s and that's probably the limit with the technology we have now. Totally not worth since you can get these CPUs as ASICs for pennies.

Now, a middle range FPGA-only chip, like middle-high line Cyclone's or Spartan's would be nice toys to attempt to make your own Pentium/K6 chipset... probably a 440lx if you push them far enough. You would be closer to something affordable to work your VHDL core code with, but still is something too expensive for many.

Yeah, from what I have read about FPGAs they just aren't practical in terms of cost and performance for a lot of projects we would like to use them for. Maybe someday in the future. Compared to a custom ASIC, an FPGA could be more cost effective and flexible, assuming the FPGA itself wasn't so damn expensive and slow.

Don't remember this being mentioned, basically emulation cores for the 40 pin Teensy 4.1 which can act as CPU replacement in PCJrs and I would assume PC and PC XT class boards, with "AT speed"
https://github.com/MicroCoreLabs/Projects
https://www.pjrc.com/store/teensy41.html

edit: guess that's 40 plus pins, 64? Not all are used and needs interposer PCB, the PCJr accel uses a Xilinx spartan not the teensy, derp.