486tang – 486 on a Credit-Card-Sized Fpga Board

It does, yes. But the DDR RAM available on the target board is DDR3 which is actually quite inconvenient for retro projects for a number of reasons.

Quite apart from the increased complexity, the most important difference is that there's a minimum speed as well as a maximum speed for modern DDR RAM, which means there's usually quite a narrow window of achievable clock rates when getting an FPGA to talk to DDR3.

I suspect that's why the author chose to use the DDR for video: It's usually easy to keep plain old SDRAM in lockstep with a soft-CPU, since you can run it at anything between 133MHz (sometimes even more) and walking pace, so there's no need to deal with messy-and-latency-inducing clock domain crossing.

Streaming video data in bursts into a dual-clock FIFO and consuming it on the pixel clock is a much more natural fit.

Indeed! I have a 486 DX4-100 that is my favorite DOOM system. It has an S3 805 VLB card currently, fast enough. Do you have a favorite VLB card for the 486 or DOOM?

Also there's FastDoom at Github:

https://github.com/viti95/FastDoom

Didn't they have the F00F bug? (Thanks, I keep misremembering) How much more Pentium do you want?

I found 10 Intel Galileo dev kits, new in box, left at our local recycling center on the "Free: Take Me Home" shelf.

And just today, I received the Intel Edison dev kit that I'd purchased on eBay.

The Galileo is a Quark X1000 SoC, two P54C cores. In-order, original 32-bit Pentium.

https://en.m.wikipedia.org/wiki/Intel_Galileo

.

The Edison is a modern System On Module about the size of an SD card but about 3x the thickness of one. It's far more capable: dual 64-bit Silvermont Atom cores, Super scalar out of order. And an additional Quark core as a system monitor, running an independent RTOS. There's also 4GB eMMC, 1GB RAM, WiFi, and Bluetooth on the module. Its quite a remarkable curiosity.

Ten years ago, Intel tried to catch up to ARM in tablets and smartphones, but it was already too late, and this entire segment of Intel was cancelled within a year or two.

https://en.m.wikipedia.org/wiki/Intel_Edison

Next up is building more recent Linux images for these via the Yocto Project and the now cancelled Intel Board Support Packages (BSP).

If you like low power tiny systems, there's a strange amount of fun to be had.

Those were actually a 486 microarchitecture with some Pentium instructions added. If you look at the documentation for them, it's obvious that they copy-pasted the 486's and search-and-replaced.

Define "486-compatible." As far as I know even intel's newest cpus can run 486 era 16-bit stuff in hardware.

But, a plain answer: Via Eden boards. still use north/southbridge architecture, and are from the mid 2000's.

It's just modern Windows/Linux that have discontinued the ability. Or, perhaps you have 16/32 and 32/64 and are unable to do 16bit on 64bit machines- which still boils down to "operating system."

By far the biggest issue though is that even the Via Eden processor is significantly faster than a 486- and lots of software (especially games) from that era used no-op instruction loops for timing and timers. This results in games like The Incredible Machine's level timer running out in half a second or less.

Intel did have a product like that but it's been discontinued: https://en.wikipedia.org/wiki/Intel_Quark

Vortex86 is probably the closest thing to what you are looking for.

I'm guessing the ITX-Llama is far less affordable next to reusing a "generic" FPGA retrogaming board.

There used to be single-chip x86 systems, but I don't know if they went all the way up to 486. You'd see them in early low power portables.

There is a branch of Via (?) in china making enhanced 486 system on a chip "586" systems. I'm on mobile so I don't have the name handy but I'm still hopeful these get cheap enough to enter the hobby space more.

Author here. You’re right—EDO or FPM would be correct for the era. But as others have noted, DDR3 is fundamentally different from early 1990s memory, and it simply won’t run at the very low clock speeds of a 486. SDRAM, on the other hand, behaves in a way that’s much more comparable to the memory used back then.

Ah that’s nice. Affordable FPGAs are always welcome.

https://archive.is/UD0vH

A review of sorts - https://youtu.be/ScwZwfS53dE

Could maybe run HL1. Maybe.

For those not aware, this is a reference to an audience comment at the HL2 E3 2003 presentation: https://www.youtube.com/watch?v=4ddJ1OKV63Q&t=200s

Half-Life 2 was but a twinkle in Valve's eye when the 486 arch was introduced in 1989. ;)

rpi are, and always have been a little bigger (and much taller) than credit cards. more like altoids tin

> I would love to see ancient tech fabbed out on modern processes.

> What's the smallest SOC you could design to run DOOM?

Depending on your definition of "modern", more than you think has been done. Intel's Quark were basically 486/Pentium hybrids but fabbed on a fairly modern (at the time) process. While Quark is no longer available as a standalone product, a derivative is part of every modern Intel processor in the form of the Intel ME system co-processor, and it's likely that a number of other Intel products (network cards, QAT accelerators, the ARC GPUs, etc) use them as system controllers as well (Quark essentially came into existence as a "formalization" of the multiple "micro-x86" implementations inside Intel being used as embedded controllers for various non-CPU products).

> What would a massively-multicore (gpu-style with multi-hundreds or more of cores) one of these run like?

This is close to what the original Xeon Phi was. Essentially 60-ish Pentium cores, with modern SMT and 512-bit vector units added. It worked ... OK? If the software development story had been better (e.g. actual first-class support in GCC) I think they could have been a much bigger success, but the need for ICC back in the ICC-costs-real-money days and initially very expensive hardware certainly held them back. At times I do miss some of their behavior.

Arguably a number of the RISC-V-based "AI accelerators" on the market are basically new spins on the same idea: a bunch of small cores, plus large vector/tensor units.

That is a cool idea for sure. It's fun to imagine where the original x86 platform ({80,2,3,4}86) would have gone if it hadn't been remade with the Pentium (superscaler).

It currently uses 44% of the LUTs and 59% of the BRAMs (out of 340 × 2 KB blocks). The chip itself is fairly large and inexpensive, though performance leans toward the lower side.