[HN Gopher] Computer-generated dream world: Virtual reality for ...
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Computer-generated dream world: Virtual reality for a 286 processor
Author : MBCook
Score : 140 points
Date : 2026-03-02 04:23 UTC (18 hours ago)
(HTM) web link (deadlime.hu)
(TXT) w3m dump (deadlime.hu)
| 01HNNWZ0MV43FF wrote:
| So they're stepping a 286 very slowly and sorta... bit-banging
| the I/O pins on it?
|
| Love it. No notes.
| st_goliath wrote:
| 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-
| experiment...
|
| [2] https://github.com/dbalsom/arduinoX86
| dividuum wrote:
| Here's a project that also does this to ensure cycle-accuracy for
| their emulator: https://github.com/dbalsom/arduinoX86
| theginger wrote:
| 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 wrote:
| 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 wrote:
| 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
| ErroneousBosh wrote:
| > 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 wrote:
| 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.
| ErroneousBosh wrote:
| > even small shops in the US sometimes approach that low
| cost
|
| It's ludicrously expensive to ship things to and from the
| US though, and since they're now paying some insane
| markup because no-one understands what tariffs are the
| prices have got even sillier.
| dsign wrote:
| 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 wrote:
| 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
| ZiiS wrote:
| 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 wrote:
| In my experience it's a couple of weeks, not months from
| China.
| ZiiS wrote:
| Depends how much you are happy to pay; but yes it has got
| faster.
| asdefghyk wrote:
| wirewrap circuit construction would be more reliable. However
| high speed (if needed ) could be a problem ? from crosstalk.
| fatnoah wrote:
| 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.
| asdefghyk wrote:
| One maybe unrecognized problem, of breadboards is not so good
| for high speed digital circuits due to capacitance
| coderjames wrote:
| For the 2D version, you might not need very much custom. Use a
| regular pen plotter and use a pen with conductive ink. These
| both exist today, though personally as a hobbyist PCB designer,
| I can get 2-layer and 4-layer boards cheap enough from JLCPCB
| or Oshpark or PCB Unlimited that I don't bother trying to make
| them myself.
| jrmg wrote:
| I always thought conductive ink had too high a resistance to
| use to make PCBs. That's not the case?
|
| How do you attach the components to it?
| dsign wrote:
| Yes, conductive ink has too high resistance; at least the
| one that works on a basis of carbon; a "trace" can easily
| have kilo-Ohms, and the metal ink interface makes things
| worse.
|
| I remember reading some "Sputnik" magazines from the 1970s
| where Russian scientists were searching for the holy grail
| of a good conductor resin. I didn't understand at the time
| why they found the (concept of the) thing so valuable; but
| now I've got an inkling...
| estimator7292 wrote:
| My last job had a desktop CNC called Volterra I think. It would
| squeeze out conductive ink, bake it, drill holes, and lay down
| and reflow solder paste.
|
| It was expensive and performed terribly.
|
| I think there really isn't any good way to improve on
| breadboards. Breadboards, in fact, _are_ the improvement. They
| 're called breadboards because we used to literally drill
| pieces of wood and do wire-wrap construction on the other side.
|
| Breadboards are good enough for the kind of prototyping they're
| for. Spring loaded contacts are about the best you can get for
| removable parts. The signal integrity isn't _that_ bad at
| modest speeds.
|
| In today's world, the next step up from a breadboard is custom
| PCBs. You can have a set of five shipped from China for the
| same price as a set of breadboards. There's no real need or
| reason for anything in between so long as PCB manufacturing is
| so disgustingly cheap and fast.
| kevin_thibedeau wrote:
| Just use a fabrication service. You can't readily make plated
| through holes and vias at home. The services do a much better
| job than any hobbyist level tinkering can achieve.
| tl2do wrote:
| 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 wrote:
| 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 Also on bluesky
| https://bsky.app/profile/pc98bot.gang-fight.com
| livestories wrote:
| Reminds me of the Tamagotchi Matrix:
|
| https://hackaday.com/2015/11/24/building-the-infinite-matrix...
| markbnj wrote:
| 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 wrote:
| Very impressive to use intel cpu without BIOS. Real hacker
| forinti wrote:
| > 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.
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