13 ms·

Computer-generated dream world: Virtual reality for a 286 processor

146 points by MBCook 8mo ago

01HNNWZ0MV43FF 8mo ago
So they're stepping a 286 very slowly and sorta... bit-banging the I/O pins on it? Love it. No notes.
st_goliath 8mo ago
I've seen a similar project a while ago and thought this was about the same thing at first: [1][2] Both essentially built a DIY chip tester for a 286 and both built around a Harris 80C286. If I understood it correctly, the goal behind this project seems simulating the rest of the PC, purely for the challenge and learning experience, documenting the process of building the chip tester (and getting mildly philosophical in the process). The other project was more directly interested in the 286 itself, undocumented instructions, corner cases in segmentation behavior, instruction cycle timing, etc. and also trying to find out if there are any difference between the Harris and Intel variants. [1] https://forum.vcfed.org/index.php?threads/286-cpu-experiments.1253659/ https://forum.vcfed.org/index.php?threads/286-cpu-experiment... [2] https://github.com/dbalsom/arduinoX86 https://github.com/dbalsom/arduinoX86
dividuum 8mo ago
Here's a project that also does this to ensure cycle-accuracy for their emulator: https://github.com/dbalsom/arduinoX86 https://github.com/dbalsom/arduinoX86
deleted 8mo ago
[deleted]
theginger 8mo ago
Looking at the amount of wires going into this, my instinct is that this cannot scale, in 5-10 years this won't be doable for a Pentium chip, at least not as an at home hobby project. But I actually think it could go the other way, and in 5-10 years you'll be able to do this at home for far more sophisticated kit, unlocking crazy amounts of reverse engineering possibilities that were once thought of as near impossible, or at least only possible for a nation state scale setup.
- st_goliath 8mo ago
  I'm pretty sure if you really want to, you could do something like this as a hobbyist with a Pentium right now. Instead of futzing with wires on a breadboard you could simply designing a PCB up front, throw the design over the fence at JLC or PCBWay, insert coin, wait patiently at the mailbox, solder your scavenged Socket 7 onto the board. The days of toner transfer and aquarium pumps are already long gone. Getting production quality, one-off, multi layer PCBs done as a hobbyist is dirt cheap these days, no government budgets required.
  - duskwuff 8mo ago
    I don't know about Pentium, but there's definitely some homebrew 486 projects out there, e.g.: https://maniek86.xyz/projects/m8sbc_486.php https://maniek86.xyz/projects/m8sbc_486.php
  - ErroneousBosh 8mo ago
    > you could simply designing a PCB up front, throw the design over the fence at JLC or PCBWay, insert coin, wait patiently at the mailbox It blows my mind that I can use free-as-in-beer Free-as-in-Speech software to design a PCB, email it to a dude in China, and get a finished working professional-looking PCB back in my hand within a week, for the price of a couple of coffees. And if I want the components stuck on too, it'll cost a little extra, maybe three coffees it costs now. If I want it really quickly then for the price of a decent takeaway curry I can have it flown over next day. What the actual hell? Edit: the slowest part of "next day" is when it hits the UK, and if I could guarantee it just gets delivered to DHL's Edinburgh depot I could drive down there in two hours.
    - mrguyorama 8mo ago
      The reality is that's just how cheap commodity circuit construction is, and even small shops in the US sometimes approach that low cost, and we've been paying crazy markup on electronics for decades. That dirt cheap board is so profitable it is using air freight to get back to you. It is literally burning money just for convenience, yet that is the "cheap" option. Electronics cost a lot to manufacture in the 70s, but is entirely automated now but for "reasons" we have only seen a small part of that savings. When you buy the "Cheap" version on AliExpress, they are still making a healthy margin, yet Americans will happily buy the exact same product off Amazon for next day shipping for 10x the cost and think they are getting a "deal" This extends to cars as well, with the F150 costing as little as $20k to build, even with "Expensive" very unionized and well compensated labor. The higher market trims only cost a little more to make but take in far higher profit margins. How much of China's supposedly "Subsidized" car price (as if the US doesn't do anything to subsidize cars) is just a lower profit margin? Things should be way cheaper to western consumers. Where does all that extra money go? "Marketing and administration", basically bloated executive suites, bloated middle management, and the pockets of Meta, Google, AWS, and Apple. Oh gee, those exact companies seem absurdly wealthy and are basically responsible for all economic growth in the past few decades.
dsign 8mo ago
Cool! But the wires! I'm not a fan of breadboards, they tend to be unreliable even for trivial circuits. We need something more affordable and practical for home PCBs[^1]. Why is it that nobody has invented a tin 3D printer, or at least a 2D version of it, i.e. a tin plotter? [^1]: I'm discouraged from home-etching by the chemicals and the dark-room part of the process.
- vhab 8mo ago
  Bad Obsession Motorsport actually went this route, you can see their custom printer on their youtube[1] channel [1]: https://www.youtube.com/watch?v=FzrZoVKT8gM https://www.youtube.com/watch?v=FzrZoVKT8gM
- ZiiS 8mo ago
  For $2,500 the Carvera Air makes very nice 2 sided pcbs with solder mask. Though even in raw materials it is hard to match a finished board from China if you can wait a couple of months.
  - wolvoleo 8mo ago
    In my experience it's a couple of weeks, not months from China.
    - ZiiS 8mo ago
      Depends how much you are happy to pay; but yes it has got faster.
- asdefghyk 8mo ago
  wirewrap circuit construction would be more reliable. However high speed (if needed ) could be a problem ? from crosstalk.
  - fatnoah 8mo ago
    I worked at a no longer extant networking equipment manufacturer as an intern in college in the late 1990's. My role was to work on software for an in-development 45Gb network switch, and a bunch of the software I wrote ran on prototype boards. Since fabricating new boards took time and was expensive, a lot of work was done to make in situ modifications that involved an insane amount of wirewrapping. One member of the team did that all day, every day as their full time job, and I was always amazed by their ability to focus consistently at that level for so long.
Jaxon_Varr 8mo ago
[dead]
tl2do 8mo ago
I'm Japanese, and the 80286 at 10MHz was huge for Japan's PC-98 scene. The V30 handled backward compatibility while the 286 ran much faster than what we had before. This project brought back memories—the 286 was the chip of my era, and it's great to see people still exploring its capabilities decades later.
- valorzard 8mo ago
  Japanese PC-98 games have an aesthetic that’s so unique. There’s this one Twitter account that posts images from visual novels from that era and they all look so pretty: https://x.com/PC98_bot https://x.com/PC98_bot Also on bluesky https://bsky.app/profile/pc98bot.gang-fight.com https://bsky.app/profile/pc98bot.gang-fight.com
livestories 8mo ago
Reminds me of the Tamagotchi Matrix: https://hackaday.com/2015/11/24/building-the-infinite-matrix-of-tamagotchis/ https://hackaday.com/2015/11/24/building-the-infinite-matrix...
markbnj 8mo ago
Ha, little fall down the memory hole. I had a Harris 20mhz 286 back in the late 80's. I thought that thing was a beast at the time. Paired it with a Conner 100MB disk and I remember my brother laughing derisively, "Who the hell needs 100 megabytes?"
iberator 8mo ago
Very impressive to use intel cpu without BIOS. Real hacker
forinti 8mo ago
> My first computer was a 286 with 1 MB of RAM and a 50 MB HDD That was the configuration I had when I went to college. I had an amber monitor that had a really crisp image and 5.25" HD floppy drives. The AT case was fantastic, I wish I had one today.

146 points by MBCook 8mo ago

So they're stepping a 286 very slowly and sorta... bit-banging the I/O pins on it? Love it. No notes.

I've seen a similar project a while ago and thought this was about the same thing at first: [1][2] Both essentially built a DIY chip tester for a 286 and both built around a Harris 80C286. If I understood it correctly, the goal behind this project seems simulating the rest of the PC, purely for the challenge and learning experience, documenting the process of building the chip tester (and getting mildly philosophical in the process). The other project was more directly interested in the 286 itself, undocumented instructions, corner cases in segmentation behavior, instruction cycle timing, etc. and also trying to find out if there are any difference between the Harris and Intel variants. [1] https://forum.vcfed.org/index.php?threads/286-cpu-experiments.1253659/ https://forum.vcfed.org/index.php?threads/286-cpu-experiment... [2] https://github.com/dbalsom/arduinoX86 https://github.com/dbalsom/arduinoX86

dividuum 8mo ago

Here's a project that also does this to ensure cycle-accuracy for their emulator: https://github.com/dbalsom/arduinoX86 https://github.com/dbalsom/arduinoX86

deleted 8mo ago

[deleted]

theginger 8mo ago

Looking at the amount of wires going into this, my instinct is that this cannot scale, in 5-10 years this won't be doable for a Pentium chip, at least not as an at home hobby project. But I actually think it could go the other way, and in 5-10 years you'll be able to do this at home for far more sophisticated kit, unlocking crazy amounts of reverse engineering possibilities that were once thought of as near impossible, or at least only possible for a nation state scale setup.

st_goliath 8mo ago
I'm pretty sure if you really want to, you could do something like this as a hobbyist with a Pentium right now. Instead of futzing with wires on a breadboard you could simply designing a PCB up front, throw the design over the fence at JLC or PCBWay, insert coin, wait patiently at the mailbox, solder your scavenged Socket 7 onto the board. The days of toner transfer and aquarium pumps are already long gone. Getting production quality, one-off, multi layer PCBs done as a hobbyist is dirt cheap these days, no government budgets required.
- duskwuff 8mo ago
  I don't know about Pentium, but there's definitely some homebrew 486 projects out there, e.g.: https://maniek86.xyz/projects/m8sbc_486.php https://maniek86.xyz/projects/m8sbc_486.php
- ErroneousBosh 8mo ago
  > you could simply designing a PCB up front, throw the design over the fence at JLC or PCBWay, insert coin, wait patiently at the mailbox It blows my mind that I can use free-as-in-beer Free-as-in-Speech software to design a PCB, email it to a dude in China, and get a finished working professional-looking PCB back in my hand within a week, for the price of a couple of coffees. And if I want the components stuck on too, it'll cost a little extra, maybe three coffees it costs now. If I want it really quickly then for the price of a decent takeaway curry I can have it flown over next day. What the actual hell? Edit: the slowest part of "next day" is when it hits the UK, and if I could guarantee it just gets delivered to DHL's Edinburgh depot I could drive down there in two hours.
  - mrguyorama 8mo ago
    The reality is that's just how cheap commodity circuit construction is, and even small shops in the US sometimes approach that low cost, and we've been paying crazy markup on electronics for decades. That dirt cheap board is so profitable it is using air freight to get back to you. It is literally burning money just for convenience, yet that is the "cheap" option. Electronics cost a lot to manufacture in the 70s, but is entirely automated now but for "reasons" we have only seen a small part of that savings. When you buy the "Cheap" version on AliExpress, they are still making a healthy margin, yet Americans will happily buy the exact same product off Amazon for next day shipping for 10x the cost and think they are getting a "deal" This extends to cars as well, with the F150 costing as little as $20k to build, even with "Expensive" very unionized and well compensated labor. The higher market trims only cost a little more to make but take in far higher profit margins. How much of China's supposedly "Subsidized" car price (as if the US doesn't do anything to subsidize cars) is just a lower profit margin? Things should be way cheaper to western consumers. Where does all that extra money go? "Marketing and administration", basically bloated executive suites, bloated middle management, and the pockets of Meta, Google, AWS, and Apple. Oh gee, those exact companies seem absurdly wealthy and are basically responsible for all economic growth in the past few decades.

dsign 8mo ago

Cool! But the wires! I'm not a fan of breadboards, they tend to be unreliable even for trivial circuits. We need something more affordable and practical for home PCBs[^1]. Why is it that nobody has invented a tin 3D printer, or at least a 2D version of it, i.e. a tin plotter? [^1]: I'm discouraged from home-etching by the chemicals and the dark-room part of the process.

vhab 8mo ago
Bad Obsession Motorsport actually went this route, you can see their custom printer on their youtube[1] channel [1]: https://www.youtube.com/watch?v=FzrZoVKT8gM https://www.youtube.com/watch?v=FzrZoVKT8gM
ZiiS 8mo ago
For $2,500 the Carvera Air makes very nice 2 sided pcbs with solder mask. Though even in raw materials it is hard to match a finished board from China if you can wait a couple of months.
- wolvoleo 8mo ago
  In my experience it's a couple of weeks, not months from China.
  - ZiiS 8mo ago
    Depends how much you are happy to pay; but yes it has got faster.
asdefghyk 8mo ago
wirewrap circuit construction would be more reliable. However high speed (if needed ) could be a problem ? from crosstalk.
- fatnoah 8mo ago
  I worked at a no longer extant networking equipment manufacturer as an intern in college in the late 1990's. My role was to work on software for an in-development 45Gb network switch, and a bunch of the software I wrote ran on prototype boards. Since fabricating new boards took time and was expensive, a lot of work was done to make in situ modifications that involved an insane amount of wirewrapping. One member of the team did that all day, every day as their full time job, and I was always amazed by their ability to focus consistently at that level for so long.

Jaxon_Varr 8mo ago

[dead]

tl2do 8mo ago

I'm Japanese, and the 80286 at 10MHz was huge for Japan's PC-98 scene. The V30 handled backward compatibility while the 286 ran much faster than what we had before. This project brought back memories—the 286 was the chip of my era, and it's great to see people still exploring its capabilities decades later.

valorzard 8mo ago
Japanese PC-98 games have an aesthetic that’s so unique. There’s this one Twitter account that posts images from visual novels from that era and they all look so pretty: https://x.com/PC98_bot https://x.com/PC98_bot Also on bluesky https://bsky.app/profile/pc98bot.gang-fight.com https://bsky.app/profile/pc98bot.gang-fight.com

livestories 8mo ago

Reminds me of the Tamagotchi Matrix: https://hackaday.com/2015/11/24/building-the-infinite-matrix-of-tamagotchis/ https://hackaday.com/2015/11/24/building-the-infinite-matrix...

markbnj 8mo ago

Ha, little fall down the memory hole. I had a Harris 20mhz 286 back in the late 80's. I thought that thing was a beast at the time. Paired it with a Conner 100MB disk and I remember my brother laughing derisively, "Who the hell needs 100 megabytes?"

iberator 8mo ago

Very impressive to use intel cpu without BIOS. Real hacker

forinti 8mo ago

> My first computer was a 286 with 1 MB of RAM and a 50 MB HDD That was the configuration I had when I went to college. I had an amber monitor that had a really crisp image and 5.25" HD floppy drives. The AT case was fantastic, I wish I had one today.