[HN Gopher] 80386DX ISA single board microcomputer
___________________________________________________________________
80386DX ISA single board microcomputer
Author : gigel82
Score : 297 points
Date : 2021-11-19 04:27 UTC (18 hours ago)
(HTM) web link (alexandrugroza.ro)
(TXT) w3m dump (alexandrugroza.ro)
| balls187 wrote:
| I didn't realize Intel switched the meaning of DX/SX between
| their 386 and 486 CPU's.
| caspper69 wrote:
| Then Intel released DX2 486s, which ran the core at twice the
| bus speed.
|
| No one is good at naming things in our industry.
| rasz wrote:
| and then they released DX4 that quite logically ran at ..
| triple the bus speed
| ahefner wrote:
| How so? SX was always the crappy version.
| wruza wrote:
| I was also confused by this statement and had to refresh my
| memories. In short, 386sx had 16/24 bus instead of 32, which
| made it 286 main board compatible. 486sx was simply non-fpu
| version.
| pjmlp wrote:
| As 386SX owner, it was also the no-FPU version.
| donio wrote:
| None of the 386 models had on-chip FPU. That came with
| the 486.
| kazinator wrote:
| Moreover, there was an 80387SX copro to go with the
| 386SX.
| jacquesm wrote:
| And, for us oldies the Weitek as well as the DSP32 board.
|
| https://en.wikipedia.org/wiki/Weitek
|
| and
|
| https://www.signalogic.com/images/Ariel_DSP32-PC.jpg
| kjs3 wrote:
| And if you're old and a bit odd, there were i486+i860[1]
| motherboards from (at least) Hauppauge, Microway &
| Olivetti.
|
| [1] https://old.hotchips.org/wp-
| content/uploads/hc_archives/hc02...
| jacquesm wrote:
| I never got my hands on one of those. But I did get to
| play with Transputers, which was another interesting co-
| processor option.
| anyfoo wrote:
| That's the point. With the 386, it means bus width, the
| FPU was separate as the 387 anyway. With the 486, it
| meant whether it had an FPU.
|
| I'm not getting into the whole controversial deal with
| whether the 486SX actually just had the FPU disabled, and
| what the 487 actually was, because there seems to be a
| lot of misconception around that that I don't want to
| inadvertently repeat: http://www.os2museum.com/wp/lies-
| damn-lies-and-wikipedia/
| gruturo wrote:
| True, but SX used to stand (officially? dunno) for Singleword
| Xchange, as it had a 16 bit bus. DX was Doubleword Xchange,
| hence 32bit bus.
|
| Then in the 486, the bus was always 32-bit (at least from
| Intel. I have a faint memory of Cyrix 486SLCs with a 16bit
| bus), and now the SX-DX indicated the presence of an
| integrated FPU instead.
|
| Bonus: the 80487 was not just an FPU. It was a full 486DX
| which just disabled the main CPU and did all the work, and of
| course had an FPU.
| guerrilla wrote:
| > Singleword Xchange > Doubleword Xchange
|
| Thank you! I knew all the difference (the same as 8088 vs.
| 8086) but never knew why those names were used. I love
| these tidbits of history.
| shoo wrote:
| > Finally I have installed 32 Mb RAM based on eight 4Mx9 70ns
| SIMM that I designed in the meantime.
|
| https://alexandrugroza.ro/microelectronics/system-design/4mx...
| vardump wrote:
| I was a bit confused for a second, but he really means 32 MB,
| not 32 Mb.
| jonsen wrote:
| A source of confusion is that memory chips are specified in
| number of _bits_ capacity, not bytes capacity. The first DRAM
| chips where 1-bit oriented; i.e. read and write were 1-bit at
| a time. Then you stacked for example 8 chips in parrallel for
| a byte oriented architechture, etc. 8 16Kb chips for 16KB
| memory.
| 123pie123 wrote:
| These things remind me of one of my first jobs as a bench
| engineer 'trying' to fix PCs
|
| the vast majority of problems back then was the power supply and
| the vast majority of the issues with power supplies was burned
| out capacitors - easily fixable.
|
| for some bizaar reason one memory that also sticks out was the
| painful compatibility issues of putting seagate hard disks
| together with conner hard disks (IDE cables) also SCSI was a pita
| with terminators not working (resistors at the end of the scsi
| cable).
|
| I built my first PC 386SX (I think it was only a 33MHz - complete
| with a TURBO button!! :o) ) with bits that other engineers had
| thrown away - literally, outside they had a skip(dumpster) with
| 386 motherboards and other stuff they deemed unfixable that I had
| to keep going through.
|
| everyone was scared of opening monitors - using long screw
| drivers to ground the tube made them (mostly) safe. I also had to
| fix a b/w (or technically black/ orange) CGA monitor to go with
| it. i still managed to get windows running on it.
| unixhero wrote:
| Good story!
|
| Everyone were correct about being afraid of opening CRT
| monitors. Repairing them is a whole other domain than PC
| electronics. A CRT ZAP from the cathode ray components can
| kill. That is not a place one should poke around trying to find
| solutions.
| jonsen wrote:
| Fifty years ago. EE school. TV lab. First day practicing TV
| repair. Two by two on high stools behind the open sets.
|
| Joe looking up from the schematic: "John, where is the high
| voltage?"
|
| John knows. Points his finger at the set ... and touch! I
| heard the zap and saw John and his stool tilt backwards. Flat
| on the floor.
|
| He was somewhat pale but otherwise ok.
| jacquesm wrote:
| And instantly a lot smarter!
| randombits0 wrote:
| Yeah, when his memory returned.
| HeyLaughingBoy wrote:
| It's amazing how complacent we get.
|
| Two times every day I duck under an electric gate that's
| fed by a 10kV (might be higher) low-impedance charger.
| Been doing it this way for years.
|
| Then a few days ago, ducking under it as usual, I
| happened to be on a slightly higher part of the ground
| and my back touched it as I was wearing wet, muddy boots.
| And I was instantly reminded why the horses have learned
| to not get too close to the fence :-)
| jacquesm wrote:
| Those can really whack you when conditions are humid.
| There is a pretty funny - and very obvious - dumb thing
| that almost every male that lives in a rural area seems
| to have to experience all by themselves at least once
| during their young lives. You don't quite realize how
| dumb you can be until that happens and then afterwards
| you will have a much more accurate idea of where you are
| on the intelligence scale.
| ido wrote:
| I wonder if I just got lucky in my youth trying to repair a
| mac classic II (at the time it was about 10 years old), or if
| the 9" CRT that must have not been turned on for years at
| that point didn't have enough of a charge?
|
| That machine eventually lived and functioned perfectly for
| quite a few more years (ended up just needing a new HDD)
| until finally dying.
| kn0where wrote:
| The Classic II (and others newer than the earliest Macs)
| had bleeder resistors to discharge the CRT automatically.
| Older monitors and TVs did not, so manually discharging was
| more important. The procedure was still to manually
| discharge the newer machines in case the bleeder resistor
| failed, but whenever I discharge the CRT of anything newer
| than a Mac Plus it's already discharged well before I touch
| the grounded screwdriver to the underside of the anode cap.
| reaperducer wrote:
| _The Classic II (and others newer than the earliest Macs)
| had bleeder resistors to discharge the CRT automatically_
|
| Was that why older/cheaper CRTs just turned off, but the
| more expensive and newer ones made kind of a "thunk"
| noise after the screen turned off?
| dan_hawkins wrote:
| A level of high voltage in CRTs is directly related to the
| size of tube and whether it's B/W (monochrome) or color
| (higher for color as you need to attract 3 electron beams
| instead of one.) In small monochrome CRTs (like 9"-10")
| cathode voltages would be in single digit kilovolts range,
| while for large color CRTs (19"+) would be in tens on
| kilovolts (like 25kV.) Bottom line is that in 9" CRT lower
| voltages are a bit safer and dissipate quicker after power
| off.
| Sunspark wrote:
| I plan to replace some RIFA caps on a 9" monochrome that
| hasn't been powered on for years but was still working
| last time it was powered on. Do you know how long it
| takes for an old CRT like that to bleed out all the power
| if it doesn't have a circuit to automatically do that?
| formerly_proven wrote:
| The dangers of aquadag charge are enormously exaggerated.
| The real danger is not that the shock will instantly
| vaporize you and everyone you love, but that when you
| disconnect the anode improperly the spark jumps to
| something-not-quite-ground and destroys electronics, or,
| when it jumps to you, you hurt yourself because you hit
| something or drop something.
|
| Off-line SMPS are far more dangerous because their main
| caps actually contain 100-1000x more energy than a charged
| CRT tube. And unlike the aquadag on a tube these are very
| low impedance as well.
| jacquesm wrote:
| You need to discount here for CRT size. A 9" will zap
| you, a big 30" Barco will happily kill you if you are not
| going to be careful, those things will put out HV at
| appreciable current. Ditto for old glass tube large
| screen color TVs.
| formerly_proven wrote:
| Yes, with big picture tubes there's certainly a potential
| for receiving a lethal shock (of course, depending on the
| circumstances even very weak shocks can become lethal).
| My point is more about risk, respect and understanding
| what you're dealing with instead of apocryphal stories
| and fear. The former is imho more conducive to safe
| procedures being followed.
| hwc wrote:
| Could one make a system on a chip 386?
| cogburnd02 wrote:
| yes.
| jonathanlydall wrote:
| Although this seems to be a 33MHz CPU, the 386DX40 was the first
| "decent" processor I had access to when growing up so was quite
| memorable for me.
|
| In my teenage years the PCs my brothers and I had access to were
| two 386DX40s each with 8MB of RAM and several hundred MBs of hard
| disk space (can't remember exactly, but pretty sure less than a
| GB).
|
| We really loved Blizzard's Warcraft II, which despite having a
| minimum requirement of 486 CPU, was able to run on the 386DX40s,
| albeit a bit slower than intended.
|
| Since we had two PCs we wanted to play together, but only had a
| parallel cable. I don't know why it was so hard for us to get
| hold of a serial cable, but the point is we only had the parallel
| one and Warcraft II would only be able to run over serial cables,
| not parallel ones.
|
| I eventually worked out a way though. The 386DX40s were actually
| also capable of running Windows 95 which had a feature where you
| could "network" two PCs over a parallel cable. I then ran IPX/SPX
| over that network which allowed us to play Warcraft II over it.
|
| The gameplay was pretty slow, but as I recall it was very
| reliable and we played quite a bit on this setup. Eventually we
| got a couple of BNC network cards and cables for a much more
| conventional setup.
| walrus01 wrote:
| If I remember correctly the AMD 386DX/40 sold for about the
| same price as the Intel 33 MHz part, was definitely faster in
| any benchmark, and in the same era when a 486DX/25 and
| motherboard was a very expensive system, matched or
| outperformed the 486 in a few benchmarks. It was very popular
| around 1992-1993 or so.
|
| In terms of ratio of price/performance in the budget category,
| it would probably be analogous to a zen3 based $175 ryzen today
| installed on a $150 motherboard.
| rasz wrote:
| 386DX40 was somewhere between 486SX16 and 20 when running
| 32bit code. Both 386DX and 386SX executed 16bit code at very
| similar speed to 286 clock for clock. 486 arch as a straight
| up x2 speed increase.
|
| https://dependency-injection.com/the-slowest-486-vs-
| fastest-...
|
| I have old 1994 catalogs listing AMD 386DX40 + motherboard
| (128KB cache) combo at a price point of three 1MB simm
| sticks, or one Intel 486DX25 processor, or one VLB graphic
| card, or one 14" VGA mono monitor :) 386SX with motherboard
| was 2/3 of that. I build whole 386 computer at the time
| spending pizza money on it (386DX40 + bunch of older used
| components).
|
| If you really wanted to compare it to today it would be more
| of a $40 board + $50 CPU situation while everyone buys $150
| boards for their $200 CPUs.
| StillBored wrote:
| So, I was there and made this purchasing decision too. And
| if you remove doom from the benchmarks you linked it
| matches what I remember. Which is that the AMD 386-40's
| where faster in pretty much all cases than the Intel
| 486SX-20's. They were also slightly cheaper at the time.
| And that fact gave me a terrible time deciding which one to
| buy, but in the end I got the 486 because it had two huge
| advantages.
|
| The first being that at the time, if one carefully selected
| the motherboard it was possible to overclock the 486SX-20's
| to 40Mhz and have a rock solid system. The second was the
| VLB was starting to be a thing. A 486 with a VLB graphics
| card was considerably faster than anything I would have
| been getting on the 386. And of course it was pretty clear
| that faster 486's could be plugged in, rather than
| requiring a motherboard upgrade. So IIRC, it was like an
| extra 15% difference in price to get a machine that was
| well over 2x faster.
|
| So, I saved my pennies and borrowed some from my parents
| and got the 486SX. It was rock solid for the next couple
| years until I managed to get my hands on a DX2. That was
| also my first overclocking experience and by far the
| largest increase I've ever managed. That machine is also
| probably the fastest booting x86, I've ever owned because
| it was running MRBIOS. The boot time to DOS was entirely
| limited by the HD spin-up time, and with a much later
| DX4-100 upgrade was one of my longest running linux
| firewall/network servers i've ever used until it died in
| the mid 2000's in a heat event.
|
| (well maybe the abit bp6 counts...)
| rasz wrote:
| >slightly cheaper
|
| Start of 1994 oem component prices:
| 386SX40, 0 cache motherboard ~$70 (mainly due to super
| cheap mobo) 386DX40, 128Kb cache motherboard
| ~$140 1MB 30pin simm ~$40 512KB SVGA ~$35
| 486SX20 CPU ~$150 486 VLB motherboard ~$150
| 486DX33, VLB motherboard ~$450 486DX2/66, VLB
| motherboard ~$650 486DX2/66, PCI motherboard
| ~$850 4MB 72pin simm ~$170 1MB
| ET4000/S3C805/CL5428 VLB card ~$150 2MV VLB card
| with 2D windows acceleration ~$300
|
| Jump from 386 to the cheapest 486 was x2 the cost of main
| components, ~$200-300.
| tssva wrote:
| A little late but you could also have used the Crynwr plip
| packet driver to run IPX over the parallel cable avoiding the
| significant overhead of running Windows 95 on a 386 system.
| jonathanlydall wrote:
| Only about 25 years too late :D, but that would have been
| cool to know about.
|
| It does make me think though about how I might have
| discovered such a thing at that point in time.
|
| I don't think I even had internet at home then, I never used
| things like a BBS and later I was never big into forums
| either. So the only way I really learnt things was either
| through fiddling (which is how I found out about the parallel
| cable networking) or through word of mouth.
|
| It also might not have occurred to me yet how to find answers
| on the internet and besides, there was no Google back then.
|
| There also wasn't any local community I was aware of that was
| into these kinds of things. So I only learnt very limited
| amounts.
|
| I guess I could have tried computing magazines which may also
| have helped, but I didn't have any real money then, and it's
| also possible that the options were very slim in South Africa
| anyhow.
| tambourine_man wrote:
| It's really hard for anyone under 25/30 to appreciate how
| hard it was for information to come by.
|
| I vividly remember loving a song that was playing on a
| store's radio and then standing there for half an hour
| until the spokesman eventually listed all songs he had
| played. I did my best to identify and memorize the author,
| so I could later look them up on a music store.
| TedDoesntTalk wrote:
| > I guess I could have tried computing magazines
|
| Here are some offline methods other people used to get such
| information:
|
| 1. magazines and "zines"
|
| 2. books
|
| 3. word-of-mouth (as you said)
|
| 4. clubs or meet-ups
|
| Online methods that pre-date google:
|
| 1. newsgroups (usenet)
|
| 2. yahoo groups
|
| 3. bbses
|
| 4. forums
|
| 5. msdn
|
| 6. other search engines, even ones that used categories
| like yahoo were sometimes effective. It just took longer to
| search to find exactly what you wanted
|
| 7. manufacturer websites. for example if you need the pin
| settings for a WD MFM or RLL disk drive, go to the WD
| website and look it up.
|
| ---
|
| It wasn't as bad as people think. It just took a long more
| time to find.
| a9h74j wrote:
| Anyone for the _Bits and Bytes_ bookstore in Naperville?
| jasomill wrote:
| Additionally, when available, information was frequently
| of higher quality than is readily available online.
|
| Even today, it's probably easier to find detailed,
| accurate technical documentation for OpenVMS and z/OS --
| where developers can't just be expected to "Google it" --
| than it is for Windows, Linux, or Apple OSes.
|
| Moreover, pre-Internet, I _never_ encountered a scenario
| where important documentation was only available in video
| form. At worst, you 'd very rarely see consumer products
| bundled with a videocassette for users who couldn't be
| bothered to RTFM.
|
| _Sharing_ information is certainly easier today, as
| magazines, user group memberships, long-distance BBS
| calls, and in-person conferences present a far more
| significant barrier to entry than the Web.
|
| The trend seems to be reversing, however, as more and
| more information once available over the Web now seems to
| be siloed in systems like Facebook and Discord that are
| neither searchable via Google nor regularly archived by
| the Internet Archive.
|
| What I wouldn't give for a "Usenet 2.0", _i.e.,_ a
| widely-used, persistent, open, distributed discussion
| system to reverse this trend.
| officeplant wrote:
| If you ever get the urge for playing it again the Warcraft 2
| package on GoG even comes with the IPX patcher you need to play
| on modern windows.
|
| WC2 is still my favorite of the bunch and it's joy to have a
| game with old friends from time to time. I also play WC1 in
| dosbox from time to time.
|
| I still have many fond memories of playing WC2 with friends
| across town via modem to modem. We were lucky that our dads
| were gaming friends that often played WC2 together over modem
| so we quickly fell into the same habits.
| jonathanlydall wrote:
| I actually bought the Battle.NET Edition when it came out,
| which added a few quality of life features from SC if I
| recall, like selection groups.
|
| But after having played SC2, I found that I don't really have
| the patience any more for the the primitive control options
| of Warcraft II.
| philistine wrote:
| Last time I played Warcraft 2, this is what stopped me from
| playing pretty quickly too; how primitive the controls
| were.
|
| Command & Conquer 3 had spoiled me with its intricately
| refined control scheme.
| jpablo wrote:
| Another way is to use Stratagus, it can import the WC2 assets
| from an original CD and play using that. We used to play on
| huge maps many years ago with several people playing over lan
| (It was called freecraft back then). I'm not even sure it's
| maintained anymore.
| officeplant wrote:
| Oh damn somehow I've never heard of this. I'll look into
| it.
| roywashere wrote:
| > And there is the original Duke Nukem (DN1, DN2, and DN3) which
| I always would have liked to have the ability to turn down the
| volume for. Playing without sound effects was no fun and with
| sound effects was disturbing for the other people in the house.
|
| Is there a good reason that most XT/AT era computers had no
| volume control for their PC speaker? I always wondered. My dad's
| XT had an incredibly loud speaker, I always felt bad playing
| Accolades Test Drive on it. When I finally bought my own XT I was
| very happy with the fact the speaker was a little less loud
| tecleandor wrote:
| I had an Amstrad PC1512 I will always remember because it had a
| volume control. It had some sort of powered speaker, so you
| could turn it up absurdly high, or lower the volume down
| reasonably (even switching it off)
|
| This is not the exact model, but you can see the volume control
| here:
|
| https://computers.popcorn.cx/amstrad/pc2086/pc2086-02.jpg
| anyfoo wrote:
| Somewhat. The internal speaker in the original PC was pretty
| much just a buzzer that was probably never intended to output
| anything else other than simple status beeps in office
| settings.
|
| It does not even have the ability to modulate its amplitude,
| i.e. its voltage level is either "full on" or "full off" and
| tones are usually played by doing that, for example, 2000 times
| a second to get a 2kHz square wave tone. There seem to be some
| (likely rather PC model specific) tricks to toggle it quickly
| enough to get some in-between waveforms[1], but overall there
| are no "volume" levels.
|
| While it's likely not very hard to have a circuit to manually
| reduce the overall amplitude[2], by the time this really became
| commonly desirable enough we probably all had sound cards
| anyway, if we wanted to play anything more prolonged than the
| system beep on it.
|
| [1] By means of inertia, the mechanical kind or the
| electromagnetic kind.
|
| [2] Or even in software, but nothing would support that.
| Firehawke wrote:
| This. PC speaker was driven far beyond its original design
| and intention. Sound Blasters, and later built-in
| clones/compatibles, changed the general outlook of sound.
|
| You'll see a shift to Adlib/SB audio start around 1987-1988,
| and by 1991 they were no longer niche. PC speaker support
| started to wane, but didn't entirely go away until Windows
| 95.
|
| How do I remember this? I ran a BBS in the 90s, and my family
| was one of the early adopters of sound cards back in 1987
| (Creative Music System, later rebranded to Game Blaster
| before Creative Labs came out with the Adlib-compatible Sound
| Blaster) and we ended up going through a few of the different
| cards over the years across multiple PCs.
| joemaffei wrote:
| I remember an old demo that would play a loop of the chorus
| of I Say a Little Prayer through the PC speaker. It was
| hard to believe that the speaker could be pushed to such
| limits.
| pkaye wrote:
| It was just a single pin on the timer chip connected to a
| buzzer so you could generate a square way at a certain
| frequency.
| oso2k wrote:
| But you could do a bit more. Here's a DOS golf game that did.
|
| https://m.youtube.com/watch?v=hMPb1UlSRpY
| pkaye wrote:
| Probably use software to implement pulse width modulation.
| I knew even 8-bit computers where people would bit-bang PWN
| to produce audio. Its just that storing all that data would
| be a major constraint in such limited computers.
| incanus77 wrote:
| > Take your time to solder all the components on the board. There
| are a lot of solder points and if you don't have patience in
| general, then this project might not be for you.
|
| Understatement.
| FullyFunctional wrote:
| This was painful to read. 14 year old me finally managed to get
| the NASCOM 2, my first ever computer. It came as a kit with
| 2,000+ solder points, but patience was never my virtual and
| certainly not at 14 year old so my work wasn't perfect and
| worse, wasn't properly checked. The original Z-80 died and I
| had to get professional help to get it working. (And learn to
| program: Z-80 in binary hex codes -- didn't get the memory
| necessary for the Microsoft BASIC until later). Still have this
| computer.
| flyinghamster wrote:
| > 12" AOC monochrome VGA monitor
|
| That brings a huge grin to my face. I had one of those, precisely
| of that vintage, which was my first VGA monitor of any type. The
| only thing different would be that it was 120V/60 Hz.
|
| It lingered on as a console monitor for many years, and still
| worked when I finally took it to the recycler a few years ago. In
| its final years, it didn't get along with some graphics cards or
| BIOSes since it was purely 640x480 VGA and nothing else, and DDC
| didn't exist when it was built.
| gadyke wrote:
| I've been watching this project like a hawk for months to see
| whether the final DMA/FDC bugs they identified get ironed out.
|
| The idea of being able to hand-assemble a 386DX SBC, ISA
| backplane and Alexandru's other ISA cards is incredibly
| attractive to me - I find hand soldering to be entrancing in the
| same way some describe knitting.
| liendolucas wrote:
| Wow, that's something impressive! I'd really pay for a device
| that can run DOS games from that era (the golden era of video
| games). Yeah, we do have emulators and all that, but having a
| real full fledged x86 retro computer running old stuff is cool. I
| don't know about the author but I think he is in a very good
| position to push this further and make it a product, I'd
| definitely buy one!
| immmmmm wrote:
| it's funny, i was wondering how i could use my old 386 cpu that i
| saved from my first computer. the memories of running slackware
| 1.0 on it is still vivid. ah that moment i got my first X server
| running :)
| yitchelle wrote:
| It is truly amazing that one person can bring up a 386DX board
| system. It is true that there are tons of docs available, but
| still to bring everything together and to get it running is truly
| amazing. The team size at any of the PC OEMs doing a 386DX design
| when it was the state of the art would be at least 25 engineers
| and managers, easily.
|
| Congrats to Alexandru for hitting this out of the park.
| gigel82 wrote:
| I've always wondered why no one came up with cheaper / mass
| produced 386/486 SOCs; are there any still-valid patents
| preventing that or is it too much work when we have powerful &
| cheap ARM SOCs that can emulate them...
| st_goliath wrote:
| Those do exist, e.g. the Vortex86 SoC[1] comes to mind.
|
| Not sure if the AMD Geode GX/LX series[2] counts, since they
| IIRC have an external support chip. Some years back I used to
| work with router boards and industrial PCs that used them. I
| still have an industrial PC sitting on a shelf with an
| Eurocard[3] sized SBC and the ISA bus connected to a
| DIN41612[4] back plane.
|
| The Geode implement a large subset of the i586 ISA tough (the
| LX also have an AES extension), but some other instructions
| are missing. I'm also not sure if they still make them any
| more, but given how many industrial products they're in, I'd
| bet there are warehouses full of them somewhere, until the
| last support contract expires.
|
| [1] https://en.wikipedia.org/wiki/Vortex86
|
| [2] https://en.wikipedia.org/wiki/AMD_Geode#Geode_LX
|
| [3] https://en.wikipedia.org/wiki/Eurocard_(printed_circuit_b
| oar...
|
| [4] https://de.wikipedia.org/wiki/Datei:DIN41612-c-federleist
| e-c...
| Crontab wrote:
| I also think it would be interesting to see how small, or how
| fast, you could make a standard 486 by applying modern
| manufacturing.
| userbinator wrote:
| Intel did that with the Quark core. (Get the datasheet and
| compare with the 486 one. Some of the diagrams are
| identical, and I recall seeing one of the search/replace
| they did resulted in "QuarkDX" showing up.)
| oso2k wrote:
| 386, 486 embedded chips were widely produced as SOCs but
| they're embedded in places you probably wouldn't look for
| them. Which is why they're SOCs. :) 586 and semi 686
| compatibles are still available in certain quantities.
|
| Today, a Pi0W could emulate anything up to a low end 486,
| Pi0-2W/CM3 could do about 486DX-100/low end Pentium.
|
| https://en.m.wikipedia.org/wiki/List_of_former_IA-32_compati.
| ..
|
| https://m.youtube.com/watch?v=8fSdLKx5HlU
|
| https://m.youtube.com/watch?v=6cXdWMOl8QE&t=241s
| agumonkey wrote:
| Aren't there 486 class cpus in space ? I thought they made
| radiation hardened designs that were sufficient for their
| needs.
| oso2k wrote:
| Yes, 386 and 486. MIPS CPUs are more common.
| cmrdporcupine wrote:
| Not an SOC per-se but PC/104 SBCs were quite common about 20
| years ago. I'm sure they're still around now, but ARM is
| obviously dominant. We used a PC104 SBC running Linux to
| control a rack of wireless radio amplifiers via CAN network
| at a job I had in 2001. I rolled our own custom Linux distrib
| to fit on small compact flash, and worked on the middleware.
|
| (aside, the manager / senior engineer there was quite forward
| thinking; the whole stack was Python before it was cool, and
| there was a proto-AJAX front end that only worked in IE
| because the other browsers didn't support it yet... dashboard
| that was super nice. Met some really smart people there).
| hmrr wrote:
| My father used to import clone PC stuff from Taiwan. The guys
| running these ops were surprisingly small usually. Some of the
| original ISA graphics cards including the weird CEG (anti
| aliasing ones) had 3 guys running the entire outfit. The guy
| writing the software was stuffing boxes in his lunch break and
| there were no managers. Even the case design companies were one
| man outfits with all the actionable stuff contracted out. It
| was remarkable.
| AshamedCaptain wrote:
| I concur. This world is simpler than people think. They share
| specs on powerpoint files and the firmware is written
| (/built) by one guy during his breaks (I was going to say
| exactly this even before I read your comment)
| throwaway29303 wrote:
| Wow! Very cool project and very inspiring! I'd love to know more
| about hardware like this but I wouldn't know where to start.
| wbsun wrote:
| With all these ARM/RISC-V based SBCs like RPi, I always wonder
| why no one every wants to make similar 8086/80386 SoCs and SBCs?
| pshirshov wrote:
| It would be so awesome if this guy may start producing and
| selling these in small quantities.
| guerrilla wrote:
| I'm doing the much easier version of this with the 8086 right
| now. After having learned how to do that, I find it hilarious
| that I considered starting with a 386SX. This is a seriously
| difficult project for a hobbyist. I'm so glad someone did this
| though because now I can just kit and mod it and skip the
| designing.
|
| Props on going for a full 32MB of RAM. No 16650 UART though? I'd
| add that.
|
| Overall, congratulations!
| pan69 wrote:
| > Props on going for a full 32MB of RAM.
|
| He did do his own 4MB SIMMs, so...
|
| https://alexandrugroza.ro/microelectronics/system-design/4mx...
| mahoro wrote:
| This is absolutely amazing and beautiful work. Congratulations to
| Alexandru!
|
| BTW can someone clarify what's the benefits of building the
| computer as an ISA board?
| oso2k wrote:
| ISA boards (main, backplane and/or add-on) are relatively
| simple to design and interface. Not having to worry about north
| bridge and south bridge chips, PnP, PCI, AGP, VLB, EISA, MCA,
| etc. makes designs simpler. Many of the period correct sound
| card chips, VGA chips, Ethernet chips, serial and parallel
| chips are still available to design around.
|
| https://github.com/skiselev/isa8_backplane
| jabl wrote:
| Probably because he previously designed an ISA backplane to
| plug it into:
| https://alexandrugroza.ro/microelectronics/system-design/isa...
| dark-star wrote:
| This is awesome, I would totally build this next week (I have
| most of the components around) but the PCB alone is over 500$,
| and I'm not sure I could solder that large SMD chip without
| breaking anything.
|
| Awesome project, but a little too expensive for me sadly :(
| detaro wrote:
| You can get the PCB a lot cheaper if you don't have it made at
| OSHPark.
| flyinglizard wrote:
| Awesome project, although I personally can't identify with
| putting such effort into reinventing the past instead of making
| something new.
|
| I suspect different people live in different periods. I've known
| people who always dwell on the past, those who are preoccupied
| with the future and those who are in the present and not
| overthink too much in either direction.
| guerrilla wrote:
| Because it's possible. Bringing up more advanced CPUs alone and
| with hobbyist tools is borderline impossible. Nothing
| revolutionary changed (Sorry Pentiums) until the Opteron, so
| you're covering an entie era by doing this and learning a ton
| that applies even today.
|
| I dislike the premise of your question though. There's no
| reason it need to be economically useful. People can just do
| things thy love and enjoy.
|
| On top of that, this question is like asking why learn finite
| automata, why not just jump straight to Turing machines and
| trying to solve P=?NP. No, that's nonsense obviously and you
| gotta walk before you can run.
| flyinglizard wrote:
| The level of expertise in the OP is way above "walking" when
| translated to EE terms. It's educational no doubt but so was
| every one of my professional projects over the years.
|
| Yes I completely agree that people should do what they enjoy
| - it's just that every now and then I see this completely
| amazing undertaking with absolutely no extrinsic value and I
| wonder. It's all a very personal vantage point of course.
| guerrilla wrote:
| > The level of expertise in the OP is way above "walking"
| when translated to EE terms
|
| I know, I've looked into doing it and this is mind-blowing
| but they're relative terms and it depends on what you
| compare it to. This is "walking" compared to bringing up a
| Ryzen machine.
|
| > with absolutely no extrinsic value
|
| Why should it? And how do you know it doesn't and they just
| haven't documented that?
| anyfoo wrote:
| A lot can be learned for the present from such projects. Older
| stuff is usually less integrated, more tolerant to
| manufacturing by hand (for many reasons, including relatively
| easy to deal with frequencies, board layout, and required
| layers), and you have plenty of "reference" implementation and
| documentation to delve into. It is a very valuable hands-on
| experience that certainly gives an edge over people who only
| know how computers are put together theoretically.
| jtl999 wrote:
| I guess the idea is if you're studying EE and related fields:
| "crawl before you can walk"
| flyinglizard wrote:
| This is not crawling by any stretch of imagination. It's
| low speed digital which is the only thing making it "easy",
| other than that it's worlds apart in complexity from a
| reasonable educational or DIY project.
| [deleted]
| timonoko wrote:
| "Interesting History" is just before your own time (of
| sentience). I would consider rebuilding 1972 computer a worthy
| task. But not some 1990 beige box from China.
| hulitu wrote:
| Why not "some 1990 beige box from China" ? Do you think this
| is not interesting enough ? An 1972 computer is more
| mecanically challenging . And finding ICs could also be
| challenging because some are not produced anymore at least in
| the west. Finding SW is also a challenge. In the end is a
| question of mostly time and component availability.
| timonoko wrote:
| I just threw 1988 turbo-button computer into garbage. I
| kept in the closet for 30 years, because it was not mine,
| and I excepted the owner will come any time and collect it.
| Now he is dead and I do not believe in ghosts.
| jazzyjackson wrote:
| doing your part. the only reason any vintage computer
| becomes valuable is that most of them get tossed in the
| trash. the kids in the year 2076 are going to love turbo
| buttons. Chinese factories manufacturing parts for
| American computers, who could imagine!
| toast0 wrote:
| There's people who are looking for that kind of stuff. If
| it's not too late, it would be worth posting it for free
| (or whatever) on your favorite local market.
| NoGravitas wrote:
| I kind of wish I had my 1990 beige box, even though it was a
| hunk of junk even for the time.
| timonoko wrote:
| It was the worst of times. You needed at least 50 Mhz to
| play MP3-files. Only rich people could afford that. And
| couple of years later you wanted to play DIVX-files and you
| needed 300 Mhz.
| NoGravitas wrote:
| I later had a 486-66, and it would only play MP3 files if
| they were 64kbps or lower (or 128kbps mono).
| FullyFunctional wrote:
| My recollection doesn't agree with you. It was a stretch
| for a 300 MHz Celeron to play an MP2 (not even MP3) - I
| was an early adopter as I hated all the analog degrading.
| userbinator wrote:
| This is an awesome project! There have been others who have made
| their own computers using as far as a 486
| (https://news.ycombinator.com/item?id=26407783 ) but making it
| IBM PC compatible really takes it to the next level. The only
| thing that would make it more amazing is if he didn't use
| existing chipsets and implemented all the glue logic on an FPGA
| (like the aforementioned 486 board) or discrete TTL.
|
| The Pentium was when Intel started to get too secretive, I think;
| there's relatively little of the low-level information that's
| needed to create hardware like this compared to previous CPUs. I
| believe modern PC designs are all entirely based on a reference
| design from Intel so if you could get access to one, it would be
| possible to make your own motherboard, but signal integrity and
| such are going to make the PCB layout much more difficult. That
| said, there are plenty of laptop schematics out there... and
| (although a group effort) some Chinese managed to make a custom
| motherboard replacement for a Thinkpad:
| https://news.ycombinator.com/item?id=15274644
| ane wrote:
| What a cool project. I really like the way he analyzed his
| failures, learned from them, and documented the process, and
| tried harder.
|
| I wonder, did he design the ISA bus by himself or did he use an
| existing one?
| pan69 wrote:
| > I wonder, did he design the ISA bus by himself or did he use
| an existing one?
|
| His own [1]. Many more projects by him [2]. Truly amazing.
|
| [1] https://alexandrugroza.ro/microelectronics/system-
| design/isa...
|
| [2] https://alexandrugroza.ro/microelectronics/index.html
| DeathArrow wrote:
| I wonder, apart from having fun and scratching some nostalgia
| itches, what are the outcomes of this? Do any of the things
| learned by doing this project help in working with present day
| hardware?
| hulitu wrote:
| You can run Windows 3.1 which has a GUI more advanced than win
| 10 GUI. But 32 MB RAM ? Is there any Win 3.1 app which can use
| so much RAM ?
| rnd0 wrote:
| I'd be surprised if the various compilers coudn't; especially
| Watcom.
| slim wrote:
| Is there any Win 3.1 app which can use so much RAM ?
|
| Maybe someone will start a new software project targeting the
| platform. That would be the second most interesting project.
| happycube wrote:
| There were some 32-bit extenders IIRC, but there's also
| Win32S.
| userbinator wrote:
| A 386DX actually has a full 32-bit address bus, so you can
| theoretically give it (almost, due to MMIO) 4GB of RAM.
| Memory testing might take a ridiculously long time, however,
| and I'm not sure if there's any stock BIOS that will handle
| it. All limitations that can be worked around, of course.
| NoGravitas wrote:
| That much RAM on a 33Mhz 386DX would run OS/2 very
| comfortably, and you could actually use all of it. Or very
| early Linux distributions, of course. Imagine a Beowulf
| cluster of them!
| FullyFunctional wrote:
| Exactly. The requirement for my first personal PC was that
| it could run True Emacs on Linux (Sun 3 at my University
| had spoiled me), but I could only afford the absolute
| minimum: 386SX/25 MHz w/4 MiB. It was a Toshiba T1800
| notebook, very nice but monochrome LCD, tiny harddrive, and
| not expandable.
|
| With 4 MiB I was able to try X11, but not use it in
| practice. 32 MiB would have been incredible.
| anyfoo wrote:
| Probably not so much. Most of Win 3.1 is actually still 16bit
| even in Protected Mode (unless you count win32s which came
| much later), so everything over 1MB cannot even be addressed
| directly. While you can probably come up with something that
| makes use of the 32MB under Win 3.1, that would likely be
| rather artificial and not very typical of what was happening
| back in the day, not just because 32MB was considered
| absolutely massive then.
|
| I vividly remember thinking how freaky it must be to have a
| PC that tests 32MB at boot (and how long it must take), and I
| think that was even during Pentium times already, not sure...
| my 486 had 8MB while many still had 4MB.
| joakleaf wrote:
| Protected mode using 16 bit segment:offset addressing could
| use more than 1 MB of memory.
|
| The segments were 64K, but the base address of each
| individual segment was defined in a descriptor table and
| could point to anywhere within 24-bit addressable memory
| space on the 286 and 32-bit on the 386.
|
| So the 286 was limited to 16 MB of ram in 16-bit protected
| mode. The 386 not so.
|
| Incidentally, I had a 286 that was happy to use all the 4
| MB of memory it had when running under Windows 3.1.
|
| I remember using Turbo Pascal for Windows, and being amazed
| that I could allocate more than 640KB -- albeit in 64K
| segments.
| anyfoo wrote:
| I know, hence why I said "addressed _directly_ ", which
| 16 bit segments (like the major Windows portion living in
| vm86) couldn't do, but they could still access it through
| windows (lowercase w, and no pun intended). EMS and XMS
| essentially did what you describe for example.
| [deleted]
| mjhagen wrote:
| Of course, electronics haven't changed, just gotten smaller,
| but the principles remain the same.
| [deleted]
| imperialdrive wrote:
| Umm, WOW... and in the name of nostalgia!
| kar1181 wrote:
| I wish I had more upvotes to give for this. I started wondering
| (completely naively) how hard would it be to just go ahead and
| design a motherboard for an old x86 CPU from scratch.
|
| Impossibly hard, though clearly not for everyone. What an
| incredible effort.
| itomato wrote:
| How long until it receives a Pentium?
|
| https://news.ycombinator.com/item?id=29046117
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(page generated 2021-11-19 23:02 UTC)