The Zeos 386SX was a speedy and competitive motherboard

[@necro_ware]

My two cents: this board can be found on TRW under zeos-mp386e. The problem with the search is that in "model" the actual model is expected, not the manufacturer name. Zeos is a manufacturer name.

[@Stuart-AJC]

I think a search for just MP386e works best, it shows a board which is very like this one

[@ShamblerDK]

Fancy seeing you here.

[@CDP-1802]

My family got a Zeos 386SX Desktop for Christmas '89, 16mhz with 2MB RAM! I played every Sierra game imaginable, and I upgraded it to a 486/66 and then to a Pentium 100, I eventually took it to college with me and used it to program 68HC11 microcontrollers. I still have the case although so many parts have been replaced it's now the "PC of Theseus" :)

[@adriansdigitalbasement2]

Wow!! Where did you guys get the computer? Mail order or were you local to Zeos? You might have had this motherboard in that case originally... I wonder what happened to the swapped out motherboard?

[@CDP-1802]

@@adriansdigitalbasement2 I believe my dad got it mail order, I remember the motherboard had a soldered on 386 and no SIMM sockets, just like the one you have. I also remembering it having this little radio shack backup battery velcroed to the other side of the case and connected by long wires, I guess Zeos was thinking ahead ;) It came with a giant RLL hard drive with an equally large controller card, it also had a Diamond SpeedStar video card and a serial/parallel/gameport card. The beat up case and serial card are all I have left, everything else got e-wasted over the years :(

[@briangoldberg4439]

@@adriansdigitalbasement2 My family also got one of these the same Christmas!!! We mail ordered it for sure. The company was a recommendation from a friend of the family who worked for IBM actually lol. He told my dad it was the best value we could get for a quality machine.

[@NotIT]

My friend in high school got a ZEOS 386 of some kind. I remember he was super into ZEOS claiming they were one of the best at the time around 1989-1990 or so. I do remember seeing ZEOS ads in PC Magazine back then too. However when my family upgraded our clone XT I ended up with a Gateway 2000 486DX-66 with VLB. Pretty swanky for the day. edit--- For got to say he mail ordered it since we lived in Michigan at the time.

[@CDP-1802]

I showed my brother this video and he said that is 100% the motherboard we had, he remembers upgrading the RAM chips to 4MB and the solder mask was black.

[@davemaki4888]

Adrian, I worked at Zeos for three years in sales. I was one of many who answered the phone from the ads in the Computer Shopper, PC Magazine and others. When the 386SX came out, the phones rang off the hook. Zeos was the fastest growing company in 1991. Great video Adrian. You are a wizard.

[@JoeBrenke1976]

My dad actually worked for Zeos as a technician in the 90s after working for Northgate Computers, another Minnesota computer manufacturer. I remember being told that the name was a play on Greek mythology and Zeos was the God of Computers. The Z-Card in the Zeos ad was their own credit card that they had at the time. Zeos made their own motherboards in Minnesota and also supplied some to Northgate for a while.

[@KellyMurphy]

I may have worked with your dad... I worked there in the 90's as well. I worked on the line building systems, and in tech support... I remember one customer on tech support was nothing but troubles and wanted us to ship out a bunch of parts so the support people she hired could parts cannon her computer to fix it. Instead we said we will refund her money, call-tag the pc and someone will be there to pickup the pc.. Suddenly she didn't want us to refund her or send a bunch of parts but just a floppy drive. Then their was the people in the returns department who ended up in jail for theft by taping a bunch of parts inside cases of computers being sent to the outlet stores... One of the store employees grabbed a random pc off a pallet and were setting it up for display with the cover off and found the parts. Contacted corp who told the store manager to put the cover back on and put it in the middle of the pallet, then wait for someone to dig through the pallet for that specific pc. Once you get the employee id(for the employee discount) record it and contact the police. After they got a search warrant, there was several 10's of thousand dollars of parts at their house, with serial #'s matching missing inventory items.

[@jasonerickson4361]

I worked at the outlet store in Arden Hills doing repairs for a short time, around the time that Micron bought them. I recently picked up a Zeos 486 DX33 off ebay. Nice little shot at nostalgia. Other than the hard drive being removed it seemed all original and fairly clean. I immediately upgraded the CPU and RAM and added secondary cache. Fun little exercise.

[@JoeBrenke1976]

@@KellyMurphy Yeah you might have, his name is Jim. I actually remember hearing about that theft, absolutely crazy. Towards the end if I recall correctly Micron started making all of the boards for them.

[@JenniferinIllinois]

That's a name I have heard in years!!! I remember seeing Zeos ads in Computer Shopper.

[@DamienMC83]

Long time viewer, first time commenter. Was super psyched when I saw the video title. I still own the first family PC we ever had, a Zeos 386SX-20 with the same case that you found in that old advertisement. It must have been a later model though, as my board has a different layout and 8 SIMM sockets. It also definitely had an external CMOS battery. I even have the original manual, in a Zeos 3-ring binder! I'm not much of a youtuber but I always wanted to make a video about it. The case is nice and roomy but is solid steel other than the facade and is super heavy. I keep meaning to pull the board to take pictures and dump the bios for TheRetroWeb but I haven't had the time. Would be willing to share pics and any info though. We got the machine as a hand-me-down from my aunt, well past the end of the 386SX's life. Probably around late 94 or early 95. I beat Ultimate DOOM on that thing on a business-card sized window!

[@dittrimd]

I currently have a complete and fully functioning ZEOS 386 branded system with the matching monitor and keyboard. This video has me curious so I will crack it open tonight to see the date codes and motherboard configuration. Thank you Adrian!

[@gusdattilo7684]

I had a ZEOS 16MHz 386SX system. Mine must have been a little bit newer because it has 8 SIM sockets. It was my first computer. My parents bought it second hand in ‘95 so it was pretty dated when I got it. It did have 8M of ram and a 40M (or 80) IDE HDD, VGA and a very nice clicky keyboard too. The case looked exactly those in the computer shopper adds in the video. Thanks for the good memories of my very first PC. One other think worth noting is the quality of the manuals that came with the machine. They were in small 2 ring binders with lots of technical details. In those days those manuals were Greek to me. Now I wish I still had that machine and those manuals. The SX16 didn’t last long. I found a second hand DX board with a 486DLC. Those were good days.

[@derekbrewer9681]

EE here, its my understanding that its the sitting that kills tants. In essence they rely on an oxide layer that's formed between the metallic plates, when unpowered for years and years the oxide breaks down enough to form an internal short. This also effects electrolytes and oil/paper/foil caps too lol.

[@nickwallette6201]

This is how I understand it too. Not sure why the 12V rail caps are more susceptible unless maybe the short doesn't show up immediately. Perhaps it's the first power-up that breaks down the too-thin oxidation layer and causes them to fail. IMO, just replace them. This is my process of introducing 386 and older boards to my collection. Got tantalums on it? Swap them out. Now you're done for another 20 years.

[@kaitlyn__L]

@@nickwallette6201 it's my basic understanding that, because the 12V was mainly a biasing current rather than active drive current (except for floppy drive motors etc, but that's not relevant to mobo decoupling caps) like 5V, the 12V ones were already "closer to sitting around" as it were. That's probably handwaving over a ton of important details though

[@oliverer3]

​​@@nickwallette6201Partly it's because they often had too small of a voltage margin, 16V rated caps were common on 12V rails so they would have degraded more in use.

[@JibunnoKage-YouTube-Channel]

So they rot over time? And they may wear out over time as well? If I am reading all the comments right.

[@kaitlyn__L]

@@JibunnoKage-KZbin-Channel all things turn to dust eventually! (Protons themselves might decay over long enough time periods.) But yeah most components are only designed for 10-20 years, maybe 50 at best.

[@KennethScharf]

The 386SX signals are close enough to the 286, that with a small amount of glue logic you can build an adapter to plug the 386sx into a 286 motherboard, and such adapters do exist. The 386sx can work with the 80287 math coprocessor as well.

[@mikebarushok5361]

Indeed, the 80387sx was an 80287 in a different package (and often higher clock speed).

[@draggonhedd]

You have to change the USB mode on the IR camera to use live webcam mode. It's in the settings there.

[@briangleeson1528]

Pretty awesome to see another board still kicking after all these years. I remember seeing The Zeos Pentium 90 as the top dog in some benchmark program I used to use. My first PC was a 386SX, too. Also, love all those old ads. We used to pour over the latest Computer Shopper, a shame we used to just toss them in the trash.

[@kisonecat]

I had a ZEOS computer! It was a 486. And I'm from Minnesota, which I guess isn't super surprising.

[@TheRealRaddicalReggie-o9l]

LoZer, ZEOS was a operating system owned by Texas oil mongule charlie hax. It was used in oil drilling robots back in the 90s baby

[@GerardPinzone]

Has anyone else heard of Soyo motherboards? Their 486 motherboards had F000-F7FF available, which made loading drivers into UMB a lot easier.

[@ilovethe70s]

I built an AMD K6-2 system using a Soyo SY-5EMA motherboard. Funny that I can still remember the model name after all this time.

[@cabbelos]

I had a Soyo D6IBA Dual Slot 1 motherboard, which was modded to accept PIII Coppermines in slotkets. I bought it off some random person over IRC. Transfered the money to this person I had never met and got the motherboard, two 850 MHz CPUs and slotkets in mail. I had Debian 2.2 'Potato' running on it, and later 3.0 'Woody'

[@CDP-1802]

A Soyo Dragon was my first ATX motherboard!

[@dustincarpenter1707]

@@ilovethe70s The first computer I bought my dad had me finance at the bank for 500 in 1997. It was a Soyo K6-2 by Avantec.

[@cchstechguy]

I was a senior in high school when that PC Mag came out and the Editor's Choice was the main reason I chose the Zeos as my first PC which my parents helped me purchase as a graduation gift. I remember being happy with the system, but of course got rid of it when I upgraded a few years later...although I do remember keeping the Zeos-branded DOS 4.01 floppy around for years.

[@rangercv4263]

Adrian - I bought a Zeos 386dx/25 with a math coprocessor from a computer catalog when it was brand new. If I recall correctly, I saw the ad in a computer shopper catalog and then did some research about 386s in a computer magazine. Zeos was rated pretty highly so I called the Zeos telephone number on the ad and placed an order for the computer. I paid upfront and Zeos shipped the computer to my house. The case was a pizza box style and the computer came with a Zeos branded monitor. The monitor was a VGA monitor. I vaguely recall that there was a battery pack attached by wires to a pin header on the motherboard to maintain the bios settings. The bios was a Phoenix bios. It also came with DOS but not windows. The first time I used windows was when windows 3.1 came out. The Zeos was my first computer. I do not recall exactly but I think with the options I chose (DX, math coprocessor, VGA, cache etc.) it cost closer to $4k, which was loads of money back then. Later when I got a new computer, I gave the Zeos to my brother and eventually it got lost in the sands of time.

[@msteele999]

The Zeos 386SX was my first retail desktop purchase. I took it into my office (at a car dealership) and connected it via serial port to the ADP Dealer Services system and did my system maintenance via terminal. Z-card was financing thru Zeos, which I did (it was a lot of money for a young guy back then)!

[@AstroParticle0]

I dealt with those plastic standoffs quite a bit when helping family and friends with computers back in the 90s and early 00s. I did eventually figure out the Bic pen trick on my own after struggling with needle nose pliers for a while.

[@jeremiahrex]

Zeos built the machines somewhere here in the Minneapolis/St. Paul area. I've heard New Brighton and Arden Hills, but never seen solid documentation around what was a factory vs a store. I've seen a couple Zeos machines and they've all been somewhat behind other machines from their time period. They seem to have stuck with AT power supplies longer than others. They used 286/386 style cases well into the end of the 486 era. Their motherboards also then had the annoying plastics clips for a long time. Since they made their own motherboards I think they built them to use cases they were already making and kept their costs down. I love the brand! I live a few miles from where they were built, though I grew up in Iowa and so never saw them when I was young.

[@spewp]

I loved Computer Shopper, so much.

[@Vermilicious]

Kudos for upping info on the board. I was hoping for a bit of probing on the jumper pins, but we got some magazine mentions and ads instead.

[@georgedyson9754]

Given the number of comments here with owners of ZEOS computers, I am surprised there is so little info about them on the web.

[@Knogle2]

39:40 Yep, white line is always -5V. Way back I used that to quickly spot and scavenge ATX supplies that had -5V, to do AT adapter conversions too. Even though very few ISA cards use the -5V

[@stamasd8500]

Shadowing is a lot older than the 386 era. I had a ZX Spectrum clone that shadowed its ROM: at boot it copied the 16k ROM into the first 16k of its 64k RAM, then turned the ROM off and write-protected the first 16k RAM. And there also was an undocumented port to which you could write to remove the write protection, so you could modify or patch the shadowed ROM code on the fly, very cool feature.

[@mariestarlight]

When I was young I loved Fractint. Brought back a bunch of memories of making really cool looking backgrounds and such by finding really beautiful sections of fractals and saving them.

[@dougjohnson4266]

I owned a 16Mhz ZEOS 386SX in the early 90's. It was great computer for that time.

[@porklaser]

What a fun video! When I'm investigating an old system I also like to dig up chipsets manuals and motherboard manuals and reviews and mag articles etc. The Retro Web has quickly become my first stop as it's go so much useful info in one place.

[@mariestarlight]

That white crusty stuff looks to me like Alkaline battery leakage. It's possible someone had an alkaline battery hooked up somewhere right there and that leaked.

[@robertleist771]

My first PC was a Zeos 486. One of the first systems with the VESA local bus. Had a matrox local bus video card. Microsoft made significant changes to video driver architecture from Windows 3.1 to Windows 95 and matrox never could get well working driver for windows 95.

[@Choralone422]

I remember seeing the ads and reviews for Zeos machines in the early 90s in Computer Shopper and PC Magazine! I also remember seeing the machines at Sam's Club briefly in the early 90s as well. I really wanted my parents to buy one as the family's first PC. My father ended up buying a Packard Bell from Best Buy in 1993 mostly because they offered the financing my family needed in order to afford a decent PC. Not surprised to read more about the fate of Zeos in the end. There was a huge amount of consolidation among the US based PC sellers in the mid to late 90s as the total cost of PCs dropped. The high margins and relatively slower pace of innovations in the PC market of the 80s and early 90s was completely upended by the latter half of the 90s.

[@dustincarpenter1707]

My family did much the same, but I'm guessing my dad paid in cash. Not because we were better-off by any means.

[@winstonsmith478]

Good-Bye Computer Shopper Computerworld Feb 27, 2009 "Once upon a time, in the late-80s to the mid-90s, if you cared one bit about PCs, you read Computer Shopper. You might only get a copy once or twice a year when you got the bug to buy or put together your own computer, but when you wanted to get deep into PCs, Computer Shopper is what you got. That was then. This is now. Today, Computer Shopper announced that it was going online only." They are no longer on-line either.

[@WooShell]

No, the voltage is not the problem with the Tantalums.. a 16V cap on a 12V line is perfectly fine. It's simply down to their age.. back then, the manufacturing processes weren't refined enough to ensure an absolutely gas-tight packaging, and some oxygen is going to reach into the blob (usually along the wires) and will cause slow oxidation of the ultra-thin tantalum layer. This becomes conductive and turns into a dead short. Today's molded plastic tantalum caps are (allegedly) less susceptible to oxidative aging, but won't live forever either.

[@helgew9008]

Then why is it almost always the caps on the 12V rails that fail?

[@WooShell]

@@helgew9008 I wouldn't claim that.. I've seen them fail in both rails equally (or at the same time).

[@bryanwann]

Zeos was big in Computer Shopper, they bought up the first few pages and the cover fold out in every edition

[@setSCEtoAUX]

I remember going to the Zeos store in Arden Hills, MN sometime in 1990 or 1991 with my dad to pick up a machine so he could use it to write his book. I don't know what happened to that machine; I'd love to have it to tinker with now!

[@twocvbloke]

With the board being essentially unpainted, it does look pretty neat being able to see the layers underneath, would be cool if the 'popular PCB manufacturers' offered that style as an option, especially as the average DIY PCB is often just top & bottom layers so would pass light through, and for those with obsessions with lighting everything up, that'd actually look quite neat... :)

[@helmargesel3972]

Thanks for the video

[@CqGD4Yi8fii1CYPa]

Oh, good grief! I bought a Zeos 386SX from Zeos direct to replace my original Compaq 8086 with only two floppy drives when the 1 MB of RAM I added and the NEC V30 cpu I swapped for the 8086 was no longer improvement enough. As I recall, I actually took out a small loan for the system (I had student loans to pay). It was a good box, although I had to be attentive enough to recognize the rattling sound I heard in the monitor was a loose screw bouncing about in anticipation of the first power-up. A few years later, I would give it to a friend of a friend ... I think ... when I moved to my first Windows box, which was a new parts build of my own. It was fun to revisit.

[@dintyshideaway9505]

Zeos was actually the Wall Street darling of it's day. It sold (a relative) massive number of systems. The "Z" card was the Zeos store card, even though they were all mail order. Zeos became Micron Computers after having been weakened by a failed merger with Compuadd. I talk about it in my video kzbin.info/www/bejne/p3S2iIB5gpidh7c.

[@davidwilliams1720]

My first PC was a Packard Bell 486DX2 66mhz. I can't the model name. It had a cirrus logic clgd5428 graphics embedded in the motherboard.

[@dustincarpenter1707]

My family's first Intel PC after having a hand-me-down Mac 512k was a similar PB system. I think it was a 5000 series. We upgraded it to a 100MHz Intel then replaced it with a 7900 series PB with a mid-ATX tower.

[@tigheklory]

One thing that is always difficulty back in the day was getting a math coprocessor working on a 386, why don't you do a video on 386 math coprocessors? Coleco Adam FOREVER!

[@awilliams1701]

This is the very reason why Epitronics replaces all tantalum caps before even attempting to boot.

[@CutieHoney]

I loved going through Computer Shopper! Brings back memories.

[@migry]

IMO it’s not worth replacing the shorted tant. There are likely other capacitors on the +12V supply anyway, and in any case there is nothing using that supply. Any ISA cards such as a serial card which will use the +12V will no doubt have its own decoupling caps. FWIW I recently bought an original 5150 IBM PC. The only fault on the motherboard was a short on the +12V rail caused by of course a shorted tant. This one had an obvious black explosion mark so was easy to spot and was the closest to the power connector. There was also a fault with the 360k IBM brand floppy disk drive, which of course was caused by a short on the +12V supply caused by one of our tant friends. This cap had no obvious mark on it, but coincidentally was also the closest to the power connector on the drive.

[@CheapSushi]

Gosh I really love the aesthetic of the big chip era; I guess it's my inner child wanting more of the lego-building like process. It's still a bit lego-like now but being able to pop in many of these large chips into surface mounted stations/attachment points is just so cool; it's like you have more blocks to play with instead of buying whole pre-made sets (modern times). But of course, as shown, you can have way more trouble shooting to do and to fix.

[@LaserFur]

3:52 The cut ground area for the Keyboard is to reduce RF emissions. Nowadays no one cares and uses clear sides, but back then boards had to meet RF emission rules. So that are of the PCB has inductors to isolate it.

[@_chrisr_]

I’m in UK and no one would have named their computer UTI as here that stands for Urinary Tract Infection 😂

[@JamesPotts]

Same in the US. I snickered when he read the name.

[@batlin]

Same thought hit me as soon as I saw that unfortunate but hilarious name!

[@mariestarlight]

UTI makes me think of Urinary Tract Infection. So that's a great name for a computer company lol.

[@MattPlachecki]

Tried to look up the address, 530 5th Ave NW, to see if the building was still there, but it looks like it was torn down and is now a strip mall and a Dominos. One interesting thing considering their Radio Realty product is that there is a realty company on the back side of the lot!

[@testingchannel5440]

The bios setup pages were exactly what my first computer had. Bring back my memories of all those test pages.

[@movax20h]

Great video. Love all the details, and researching old magazine too.

[@mbilden]

We used these in our accounting office in the mid 90's. Zeos was later bought by Micron to build their "house brand" computers. For a while they had an outlet store where the Menards is now on 394 W.

[@retrozmachine1189]

The eval label on the board isn't necessarily a sign of it being a test/eval card from Cirrus. The chip manufacturers would usually give full circuits and board layouts as examples for the manufacturers to use as a basis for their final products or indeed evaluation purposes. Asian factories would take those reference designs as they were, including all the text, and mass produce them for retail, and that's not even taking the cloners into consideration that would simply copy someone else's board right down to the text overlay.

[@MegaFonebone]

Used to love to flip through Computer Shopper and just salivate over the possibilities.

[@2009numan]

it wasn't radio relay Adrian, it was radio realty

[@johngangemi1361]

My first PC was a 80386SX.

[@MNGoldenEagle]

Well dang, this hails from my hometown! Wish I had heard of this back then, though I would've been just a kid at the time. 😅 That's a really cool find, Adrian!

[@senilyDeluxe]

I have a 386SX with cache memory, but it's running at 20MHz and it's only 32k of cache. Don't ask what motherboard it is, young me built it into my desk and to get it out I'll have to remove everything from that desk. Interesting is that it came with MRBIOS (which I've heard is a third party upgrade which means no mainboard has ever left the factory with MRBIOS on it, so someone must've upgraded the BIOS long before 1998). Speed600 reports 28MHz with cache enabled (no I haven't checked any jumper settings if they enable 0WS)

[@zeos386sx]

You have my complete and undivided attention.

[@briannickel5131]

It's wild that you've been tinkering with PCs for, what, 35 years, and you're still discovering weird incompatibilities that can brick your system. It's fun to play with this old stuff but the level of standardization and true plug-and-play that we have now really is great. Going back to early '90s hardware really makes you appreciate it.

[@krad2520]

The DIP RAM chips may have been antiquated by the time that the motherboard came out, but they *are* convenient for the fact that there won't be anything to block full-length expansion cards from fitting properly in any slot.

[@crunchysuperman]

We had a CMM at work that had a retrofitted contol that ran on a ZEOS 386 in a desktop case, a ZEOS Ambra, IIRC. I also remember their high end tower machine was called the ZEOS Pantera - either a 486 or early Pentium. They were kaput not long after that.

[@piwex69]

In January 1990, same date as the PC Magazine issue you had shown here, I purchased my first own PC. And it was XT 10Mhz clone with 1.2MB, 360kB floppies and 10MB hard drive. And it cost 600USD. This shows how drastically delayed was the technology adoption in CEE countries in the early nineties. I kept the “original IBM PC” case my machine came with until the 486 DX era. I miss the rapid advances of pc architecture at that times.

[@FilthPig2004]

Hakko FR-301 Temperature Range 660 °F - 930 °F / 350 °C - 500 °C Isopropyl alcohol autoignition temperature 399 °C (750 °F; 672 K)

[@IDPhotoMan]

Had a MONSTER tower Zeos 486-33. It was soooo awesome.

[@richardnixon8795]

I could choose between a fully-loaded PC-XT w/EGA card and monitor, or a Zeos 286. I went with the Zeos 286 for a couple of reasons. 1 - it ran at 12MHz where most others ran at 10MHz, and at the time, the RLL drive was quite a selling point for Zeos. Most competition used Seagate ST225 20MB MFM drives. Using RLL basically increased capacity to 32MB for the same price. They sold a 286-12, 32MB "RLL" hard drive, 512K RAM, 1.2MB floppy, "Deluxe" AT-case, 101 keyboard, serial/parallel/rtc card, Hercules-compatible video card, and 12" amber monitor for $1295.

[@pianoman4Jesus]

I also worked on a system with one of these same boards. At @28:16 Zeos company credit card. At @32:51 I recall Adaptec had a 16-bit ISA RLL controller. A full length card. That would NOT work on a 386 DX system. 386 SX was the fastest system that board would work in. At @36:32 Yup, the Zeos had the Adaptec controller... thought so! 🧐 Nice to see one of them again. 👍

[@LatteLover]

Love the semi transparent board

[@shmehfleh3115]

A motherboard a whole lot like that one powered the very first PC I owned. It was also a 386 SX-16 with DRAM chips on the board instead of SIMMs. I remember that one of the parity chips went bad on it, and I had to find a replacement. Back then, they were still carried by boutique computer stores, although it took a lot of phone calls to find one in my area that had them in stock. That computer eventually became a 486 SLC-33, which in retrospect, wasn't a particularly huge upgrade. But it was all I could afford on a pre-teen's budget.

[@danleedev]

My boy's mom had this system. Lotus 1-2-3 and Harvard Graphics. WordPerfect 5.1. A VGA monitor and Star NX-1000 attached. Serious business for the time. I was still an Atari 8-Bit user at the time. It was my first experience with the difference between a gaming system with some apps and a powerful business system.

[@greenmoose_]

I used to play with Fractint on my dads Tandon 386SX/16 as a kid! Good memories!

[@Zadster]

My 2nd PC (or rather my 2nd motherboard) was a 386SX20, I bought it unboxed from am amateur radio rally. It was supposed to be an SX16 but was mis-labelled. It was also supposed to be without memory ("oh that's the cache memory") but had 2MB onboard. Added to the 2MB I bought, it was a very respectable performer indeed, quite a lot cheaper than the 386DX mobos. I also ran FractInt! Unusually, the CPU was on a daughterboard, so you could in theory swap it.

[@beatadalhagen]

The height of that BUS 386/SX brings back a memory, one of these magazines had an advert for a system board with an optional microchannel(!) extension that added extra card slots at the bottom. I wonder if I can find it again, would have been around '89-94 I think.

[@RowanHawkins]

The key switch was a keyboard lock circuit shorting those pins will cause the keyboard to not be functional. There was a 5 pin header version with pin2 as NC. 1&3 were the power led and 4&5 were keylock.

[@TrevorKevorson]

I'm fairly certain we had that monitor on our first PC in 1990. The PC was a Schneider Euro PC (XT based PC with 512MB Ram and a 3.5" floppy all built into a long keyboard). My dad built a small "office" for the PC under the main staircase in our house (think of Harry Potter's bedroom but with a shelf for the monitor, and another for the PC and a Star LC10 printer). I spent many hours in there programming in GWBasic or playing games in Hercules mode.

[@Nukle0n]

Maybe the keyboard port was fitted manually and they didn't have the big plane there to make it easier to solder?

[@Allank7]

@10:47 Fun fact - Upper chip (Odd) label is a typo: "BIOS PUS". :D

[@oldgrizzlygamer]

Z-Card = Zeos Credit Card. Back in the day a lot of PC manufacturers offered a credit card of some kind.

[@OzzFan1000]

I remember sitting with my heavily upgraded Packard Bell 486 reading PC Magazine and Computer Shopper and seeing ZEOS winning awards for the performance of their Pantera line of Socket 5 Pentiums and wanting one so bad. It's a shame that I can't seem to find any ZEOS systems in the wild to add to my collection, not that I really need another computer in my collection. By the way, I still have several copies of my old PC trade magazines (PC Magazine, Computer Shopper, Windows Magazine, BYTE magazine, etc). Maybe one of these days I'll get around to buying a hand scanner to digitize them and upload them for posterity's sake.

[@marcseclecticstuff9497]

I still have the Zeos Pantera-90 I purchased back in late 1994. I purchased a Zeos monitor at the same time. Unfortunately, the monitor died in the 90's, the hard drives have now all died which is disappointing. By far the biggest computer I ever owned, probably close to 24" tall! I had every PC Mag, Computer Shopper, and BYTE magazine stored @ my brother's place after getting divorced. Sadly he died from cancer and his wife, whom I got along with very well, had the Sherriff remove me from the property when I went to get basically everything from my house that was stored there. Within a week she sold the property and the new owners 'disposed' of my property long before I could even get a civil suit filed against her. Lost just about everything. Luckily, I had already gotten most of my old computer stuff out before she went insane.

[@slightlyevolved]

I remember seeing Zeos ads in PC Magazine all the time. I really wanted one. I'm not sure what it was about them that caught my attention more than other brands, but they've stuck out. I've never once seen one in person though. Also, ahhh, for the days when a magazine was 200pgs and actually spent money on extensive reports.

[@definitelycasualpcs8789]

I never heard of zeoa either. And then I found a zeos 486 and early pentium based ones and apparently they were pricey units back when.

[@Alcochaser]

ZEOS was a HUGE brand back then, probably above dell back then. Micron got a hold of them and they disappeared. I don't think they sold motherboards separately, just whole computers. But since they were standard, people would upgrade them.

[@chuckthetekkie]

$1400 was definitely not cheap in 1990. My parents certainly couldn't afford that with their combined income. The only "computer" I had at that time was an NES. My first PC was a hand me down 486 Epson I got from my Aunt who got it from her boss because she installed Windows 95 on it and it was Blue Screen of Death city. So my first PC wasn't even fully working. It sucked not having money,

[@MaxxJagX]

Yea, back in the day I got mostly hand me downs. Either from pawn shops or from a friend who was able to afford things (mostly in the 90s at this point)

[@cliffshockley4406]

I believe I paid $1,800 for my IBM PS1 386SX 16 in 1990, that was with a monitor so I believe the pricing on this is pretty comparable. For reference I was 13 years old and worked the entire summer on a farm to save up the money to buy the computer.

[@JamieStuff]

My parents had the 386SX-20 version of that computer. Aside from the usual OS issues, it ran flawlessly for many years. Granted, it rarely ran anything other than WordPerfect and Lotus 1-2-3. Well, those and Minesweeper...

[@thirstyCactus]

I think that 3 Ohm you measured initially indicated a bad cap, and once voltage was applied, that caused the part to fully short. As you said, +/-13V is not used by the motherboard and so should measure high resistance.

[@shireoryx6153]

My 2nd ibm compatible. I thought I was a Rockstar with "SIMMs" and if I remember correctly, extended or expanded memory capability, but quickly started Jonesing for the amd 386 dx 40.

[@SyphistPrime]

I'm a bit too young to have grown up with systems like this (kinda wish I did sometimes because they are incredibly interesting and seem leagues easier to repair than modern parts) but I am a Minnesota native. Did not know Zeos was a thing, let alone in my state. That's a cool piece of history for this era.

[@GreenAppelPie]

They were repairable but even back then, they were more likely not worth the effort

[@SyphistPrime]

@@GreenAppelPie maybe by the end user, but generalized computer repair was a very viable business until about a decade or so ago where it started to decline. I worked through some of that in 2017 or so and the business was basically only getting by from SSD upgrades. For people who paid $2000-$4000 for your system in the early 90s I'd imagine they'd be much more inclined to try to repair and upgrade than to buy a new system. With that said though, component level repair would've still been more niche. I'd imagine they'd be replacing stuff like expansion cards in full rather than replacing components. But keep in mind, these computers have way more expansion cards than modern ones, to the point of RAM and storage being soldered to the mainboard via a bga.

[@douro20]

Nan Tan Computer was what is now Clevo Corporation.

[@SkipsHappyHour]

What a super fun video. I loved the Fracinit part. I used to nerd out on it.

[@jimechols4347]

I remember zeos towers along with northgate pc's from the ad's in byte magazine from around 1986.

[@peterjantzer4767]

First PC I bought for the family in 1991 was a Zeos 386DX20. Wish I still had it.

[@mar4kl]

29:00, 386SX PC with 32MB HDD, 512kB RAM, etc. stingy - Not at all stingy, for the time. In January, 1990, when this ad ran, most people weren't running Windows yet (Windows 3.0, considered by many to be the first viable version of Windows, wasn't even released until almost 6 months later), and for most buyers at the time, it was pretty much a choice of 512kB of RAM or 640kB. Many computers were sold with 1MB RAM, but unless you knew how to use a program like Quarterdeck QEMM, you had no way to use the top 384kB of that RAM. (DOS 5.0, the first version of DOS to have QEMM-like functionality built in, didn't come out until a year and a half later.) Few Intel-based computers were purchased with more than 1MB RAM in 1990, unless that additional memory was on a LIM EMS Expanded Memory card such as the Intel Above Board or the AST RAMpage. Even those only gave you additional memory for things like large Lotus 1-2-3 spreadsheets; you couldn't load or run software in them. 512kB was plenty for running the popular DOS software in 1990. Anyway, DOS was usually included with new computers at the time, but I'm wondering if the lower price included DOS 3.3, which was all a computer with a 32MB or smaller hard drive would have needed, and maybe DOS 4.01, which supported partitions larger than that, was therefore mentioned specifically in the upgrade package. Anyway, for comparison, the mighty 386DX/20 based system that I mentioned in my earlier comment, with 4MB memory on the motherboard, a 90MB SCSI hard drive and controller, VGA graphics and dual diskette drives set me back just over $4200 about half a year before this ad ran. (And 3MB of that 4MB RAM went unused until I upgraded the computer to 8MB about 3 years later and installed Windows 3.1!)

[@rager-69]

You skipped the part where they mention (right before the two locations) they sold through Sam's Club. There may have been a lot of these across the country back in the day.

[@FordGT40MkIV]

You mentioned the position of the keyboard controller relative to the keyboard connector. It’s a trade off of routing length for all the CPU complex signals (~15-20) vs the keyboard connector signals (~4?). The connector signals are also much slower.

[@rasz]

BIOS and Keyboard hang off ISA bus, and ISA is conveniently right there in left corner :) The only additional signals you need to route from the chipset are two /CS for both.

[@siberx4]

It can often take a bit more current than you expect from a bench supply to get shorted components to heat up meaningfully. The heat is the voltage times the current, and for very hard shorts, the resistance is super low so you don't get much power dissipated. 0.5A at 0.8V is less than half a watt (still at least visible because thermal cameras are quite sensitive though). Bumping that up to 1A would have quadrupled your wattage to nearly 2W, and made things much clearer much faster. Note that the power curve with current (for resistive loads) is exponential though (I^2*R) so don't go crazy, but depending on the short it might take 1-5A to get a clear culprit showing up on the thermal camera.

[@fattomandeibu]

For flash memory, which as you know has a limited write tolerance, will sometimes lock themselves into read-only mode when getting low on re-writes to prevent loss of data. Maybe that CF card utilised this, and the vintage computers won't recognise it in the read only state.

[@TheLemonhawk]

I do remember the the Zeos brand, as I lived in Minneapolis during the 90's. Instead of Zeos, however I bought a Gateway 386 sx. I spent a lot of time using a 1200 baud modem and communicating on FIDO net. The Gateway replaced my clam shell Kaypro 2000! I started with an IMSAI to an Osborne then the Kaypro.

[@codahighland]

I had a Zeos 486 DX2/66 back in the day.

[@MicrophonicFool]

Fujikama was the company that eventually bought out the first computer retailer in Canada I got my start in. (The Steal's People in Toronto, Hamilton and Ottawa)

[@SlavicCelery]

You said that the brown line wasn't shorted when you first checked. But, you did detect the short on the second cap. You found both bad caps initially. Just kinda funny in hindsight.

[@borisborisov195]

My first PC that was gifted to me was Unisys 386sx 16Mhz. Was very old in mid 90 but I've managed to get in internet using DOS software. Do you have an image on that CF card that you are using for testing?

[@cleanycloth]

35:32 Always wanted a Urinary Tract Infection computer…! Who comes up with these names??