Found this in storage, anyone know what it is?
Posted by alex123fire@reddit | vintagecomputing | View on Reddit | 71 comments
Posted by alex123fire@reddit | vintagecomputing | View on Reddit | 71 comments
Pro_Ana_Online@reddit
It looks like an Intel 286 8mhz AT motherboard with 512k of RAM. It also has an EEPROM (the chip with the pea-sized glass circle) which is missing a sticker that normally covers it so it's undoubtedly erase/corrupted at this point due to UV light
Given all that, and its condition, I would consider it e-waste short of someone really dedicated wanting to use it as a project. It's worth maybe $5 to someone.
tes_kitty@reddit
That's a Microcontroller, probably the 8042 for the keyboard port. This looks like an 8742 which uses an EPROM for the program storage. Even if stored in a dark place, it might have lost its programming after about 40 years.
(EPROM has a window, EEPROM doesn't)
Accomplished-Ad-6586@reddit
And there's one in the bottom right with the window uncovered. Uh-oh.
NMI_INT@reddit
Needs a significant amount of UV light to wipe it. I remember in college we had eprom erasers.
Accomplished-Ad-6586@reddit
I was thinking about age along with storage. I know to erase quickly you basically put under intense UV-C for about 30 minutes, but over time any UV can erase parts of the eprom.
Zuofu@reddit
IBM AT motherboard, 5170. https://theretroweb.com/motherboards/s/ibm-at-type-5170-type-3-68x3832
Year3030@reddit
They were bragging by putting 512k ram on it.
niall135@reddit
That's because Bill Gates said no one should need more than 640k... at Comdex 80
Flynn_Kevin@reddit
That's urban legend, Gates has denied saying it. 640k was the DOS hard limit. 1M total, with 384k for BIOS and 640k for the system to address.
niall135@reddit
I'll have to dig out the clip, it's on a cdrw I labled "funnies". ....... I keep too much s**t
alex123fire@reddit (OP)
Thanks! So brass or steel wire wheel to start the restoration?
Flynn_Kevin@reddit
Toss it in a bath of 40% nitric acid for a few days, it'll clean right up.
tes_kitty@reddit
No, that would destroy the board. You can wash it though. Some people put their boards in the dishwasher (with only a small amout of detergent), then let them dry for a few days before powering them again.
LadyZoe1@reddit
Yes. I worked for an avionics company designing military hardware. Dishwasher after SMD assembly. Obviously no relays or similar components,
Ded_diode@reddit
Likewise, in the late 90s I worked for a PCB manufacturer. We just ran most of our products through a commercial dishwasher before final QA.
tes_kitty@reddit
It's also a good idea to remove all socketed ICs first.
nicetuxxx@reddit
I wouldn't try it with old hardware. I has always used Isopropanol and an old toothbrush. First, clean it with a dry brush to remove all dust, then clean it with Isopropanol. But no water. Anyway, i think it isn't so tasty when you clean your mainboard in a dishwasher. 😁😅
tes_kitty@reddit
You're not supposed to wash it with dishes... And old hardware should have less problems with water than new hardware.
You can also take it out after washing and then rinse it off with isopronanol to displace the leftover water.
nicetuxxx@reddit
Of course without dishes together. 😊
Anyway, i got good results all this years with my method of cleaning.
tes_kitty@reddit
No problem. If it works for you, then continue doing it your way.
wootybooty@reddit
Did you say that because you’re trying to dig for gold? Acids are better. But the best thing would be to clean it with a toothbrush and alcohol and let it rest in peace at minimum 😂
Baselet@reddit
All you need is a blowtorch and a garbage bin.
docshipley@reddit
You're trolling, right?
A toothbrush or stiff paintbrush and 91% isopropyl alcohol to clean it. Vinegar and toothbrush to clean contacts if they need it.
ariadesitter@reddit
wish i had a 286
ryfromoz@reddit
486 dx 100 was the goat
PoopMasterClay@reddit
485 dx2 was the goat
AppropriateCap8891@reddit
DX-2 100. The DX only went up to 50 MHz.
Dramatic_Surprise@reddit
i remember picking up an Am486 DX4-120 from a mate who "upgraded" to a Pentium 75
Wfflan2099@reddit
You could brand cattle with a P 75.
GreggAlan@reddit
I got a good blister off the green factory heat sink on a Cyrix 5x86 after barely brushing a fingertip against it.
Kitchen_Part_882@reddit
If your friend was playing Quake, that's a valid upgrade, my DX4-100 was not happy with Quake at all.
It was around the time that the MMX chips came out for me, so I got a 166MHz one of those (along with a new motherboard and RAM instead).
codykonior@reddit
I just got a 486DX50, not sure if it works yet, or if I even have matching memory.
I read they were unstable because they used a 50MHz FSB.
GreggAlan@reddit
Fast L2 SRAM chips are needed for 50Mhz bus. I had a Micron PC 486 I ran an AMD 5x86 ADW in at 4x 40Mhz, with a VLB video card. It would post and boot at 4x 50Mhz but crashed at the Windows loading screen. If I disabled L2 it would run just fine at 200Mhz but was extremely slow.
IIRC it had 70ns or 80ns (or possibly 100ns) L2. I couldn't afford 50ns or whatever was the fastest available. No eBay yet for easy finding of cheap old parts, and sellers in Computer Shopper mostly had the idea that recently obsolete stuff was actually worth a shedload of money so they'd happily let it gather dust in their warehouses. $500 for an ST-225 MFM drive while a 100 meg IDE plus ISA multi I/O card cost much less...
Those were the days when simply putting faster ns RAM in could significantly speed a PC up. The factory ratings typically put the read and write readiness somewhere near the middle of the timing windows, comfortably enough before the end of the timing so if something caused a slowdown it wouldn't crash from a RAM read or write error.
But if you put in RAM fast enough that it was always ready right at the start of every read and write window, they would complete as quickly as possible so the computer could move faster to the next one.
It was really nice to put 100ns RAM into a PC rated for 180ns and have the RAM test ticker go from *tick*tick*tick*tick* to *BRRRRRRRRRRRRRRT!*
MaelstromFL@reddit
They had a tendency to over heat. I had one, the sucker was blazingly fast for the time. But, basically operated as a space heater!
AppropriateCap8891@reddit
That they did. First CPU heatsink and fan I ever owned were for that system.
AppropriateCap8891@reddit
Not so much unstable, but unstable unless you had the right motherboard and VLB video card. But with the right ones they were incredible.
Kenny_WHS@reddit
God I remember when I switched my dx2-66 for an AMD 5x86 133. Yeah the fpu wasn’t as good as intel, but damn I enjoyed my pseudo Pentium 75 for quite some time.
AppropriateCap8891@reddit
But the FPU also did not have the infamous "Pentium Bug".
And I never heard that the FPU was not as good as Intel, other than from Intel themselves. In fact, they got in quite a bit of trouble over that, as every FPU before the Pentium was actually designed by AMD. That was part of their agreement, AMD designs the X87 chip, and got in return the rights to make the X86 chip.
An agreement that worked fine, until that arrangement ended and AMD started making their own 486 chips.
I still remember when Intel became the laughing stock of the industry after their "Clown Calculator" ad. And they had to eat a lot of crow when people in the industry who knew pointed out that at that time even the Intel X87 chips were designed by AMD.
Zardoz84@reddit
AMD's 486DX5-133
Royal_Stay_6502@reddit
Had one also. 🫡
MisterEd_ak@reddit
I have a 486 DX4-100 at home.
pinko_zinko@reddit
Of a different era
Rusty-Swashplate@reddit
Built end of 1985/early 1986. About 40 years old!
Inevitable_Bunch6912@reddit
circuit board
MagnumCumLoudEh@reddit
Oh man, it doesn’t even have the 80287 math coprocessor. Ya know that thing had an OG SoundBlaster (tm) audio card.
Dear_Challenge_6127@reddit
That is a very old AT format PC motherboard.
willywonka42@reddit
Zoom in on that grey square and you'll see its an Intel 286. Nice! Google that chip some more and you can find out more details.
ITfarmer@reddit
Once upon a time, I had to add a math-coprocessor to the family's 286. It made our teenage late night drunken Lynx golf games run a few seconds faster per swing.
Also sporting a crisp 4 color 14" CGA CRT display. That was a high-tech basement.
Ded_diode@reddit
Windows 2.1 was top of the line! I vividly remember learning how to double-click.
Dannynerd41@reddit
that is a at clone mono
Ok-Hotel-8551@reddit
Computer
Thick_You2502@reddit
AT Motherboard
baddingo3@reddit
its a ballast amplifier card from the 70s
Der_Unbequeme@reddit
my 2nd Systemboard.
Too slow, RAM expansion card needed, so i had switched to a 80286-12 Neat-board and powered up to 16mhz, 1024kb RAM and an Adlib Card.
linuxknight@reddit
Chuckle. My first computer, the TRS-80 Model 1 in '79 had 4kb of memory.
garth54@reddit
Something from a time where you could have AMD, IBM and Intel contribute chips for the same board.
1quirky1@reddit
And, apparently, a chip every country that has ever produced a chip.
1quirky1@reddit
A motherboard that appears to have a chip from every country that ever produced chips.
Bulky-Strategy-3723@reddit
Dude you got a Dell
Choice_Magician350@reddit
🤣🤣🤣
Kiwi_eng@reddit
It should say on the PCB with a date on the BIOS chips, the earliest IBM 5170 motherboard.
blinkyknilb@reddit
On board DRAM... at one point a megabyte of those little chips was about $1000.
jrgman42@reddit
Looks like some sort of electrical device.
clamdomain@reddit
AMD and Intel on the same board. weird.
BubbaMc@reddit
That was common in those days. My 5150 is the same.
IJustWantToWorkOK@reddit
Looks similar to a flaky "286 from hell" I had back in the day.
For reasons unknown, it would work with either a hard drive, or a floppy connected, but not both. CMOS battery was shot, and there was no on-board BIOS configuration. So to boot it, you connected the floppy, ran the BIOS setup to tell it it had a hard drive, then quickly power down, connect the hard drive, disconnect the floppy, and hope you did it quickly enough that the BIOS remembered it had a hard drive.
Literally no other way to get data into this machine except the modem or serial ports.
Round-Brother-4863@reddit
Motherboard.
Limp-Ad-9001@reddit
From chatgpt
Board Overview
Full-size AT-class 80286 motherboard (~1984–1987). Fully modular, ISA-based system, no onboard peripherals.
⸻
Top-left → System RAM • Chips: NEC D41256 • Each = 256 Kbit (32 KB) DRAM • Banked (parity layout)
Result: • Typically 512 KB to 640 KB RAM • That’s the usable DOS memory ceiling
⸻
Right side → Expansion slots • ISA slots (8-bit + 16-bit)
Used for: • Video card (CGA / EGA / early VGA) • Hard drive controller (MFM / RLL / early IDE) • Serial/parallel I/O cards • Sound (if upgraded later)
⸻
Center → CPU + logic • Intel CG80286-8 • 80286 CPU • 8 MHz • ~1984
Supporting chips: • Bus control • Address/data handling (74LS logic)
⸻
Above CPU → Empty sockets • For: • 80287 math coprocessor • Optional ROM / board-specific logic
⸻
Lower center → BIOS • EPROM chips (27xxx series)
Function: • System startup • Hardware initialization • Bootloader
⸻
Bottom-right → Clock • 16.000 MHz crystal • Divided → 8 MHz CPU clock
⸻
Operating systems this ran
Primary: • MS-DOS (2.x → 6.x)
Also possible: • PC DOS (IBM version of DOS) • DR-DOS (faster DOS alternative)
Higher-end / niche: • Xenix (Microsoft UNIX variant) • SCO UNIX (early versions)
Early GUI layer: • Windows 1.0 / 2.0 / 3.0 • Runs on top of DOS, not standalone
⸻
Typical real-world setup • CPU: 80286 @ 8 MHz • RAM: 512–640 KB • Storage: 10–40 MB HDD • Graphics: CGA or EGA • OS: MS-DOS + optional Windows shell
⸻
Bottom line
Classic 286 AT clone motherboard, built for DOS-era computing where the OS, storage, video, and I/O were all separate add-in components.
Equivalent-Radio-828@reddit
Don’t you know any Greek? That guy. Zuofu
Kakariki73@reddit
Omg, I recognise that board, bought it at some computer fair somewhere in the late 80s as a young boy, it was my experiment board.
Never knew it was IBM or anything, couldn't care less because I learned my way into PC tech with this board.
Memory unlocked 😆
msalerno1965@reddit
Looks like a standard AT motherboard. It's been a while ;)