I’m glad you’re back! Maybe you can swap the crystal on the motherboard while running the the 386 upgrade? I suppose you’ll run into the clock limit on those old chipsets. Of course there are 20mhz 286 chips too. Perhaps a fastest 286 ever test?? 60ns RAM, 0ws and an over clock!

Your channel brings back so many memories I used to collect older CPUs too

Absolutely the best nerd-pron on KZfaq.

What happens if you stack the 386 upgrade on top of the cache upgrade and run cache check?

Great to see you back. Indeed, my first thoughts on the cache upgrade were also that it must have had some software. The SX/Now needed a tool to enable its own cache, but it is doubtful that it would work on your upgrade board. Suppose it wouldn't hurt to try it if you could find it. Seems the Tandon and Toshiba were not the exception, then, meaning the 386 is for sure slower than the 286 at the same clock. Good to see this confirmed.

I miss those day when i could do 80 MHz on amd 386 DX 40 MHz with crystal change. I had a realtek vga with 256K memory :D

I remember Evergreen making these overdrives when I was still a kid, but already passionned!

Glad you are back! Thank you very much!

In the late 1980s there was a DIY project in the German c't magazine for exactly that purpose: 386SX onto a 286 mainboard. Project was called PAK SX (PAK = Prozessor Austausch Karte = CPU exchange/swap board)

Good to see, you're back 🙂

Your channel is awesome. It’s great to see the old chipsets like UMC, Chips, etc.

Very interesting, rare stuff. Loved the video.

i had high hopes for the adapter thing..... great to see you back! servus aus österreich^^

I still see the burn mark on your at power supply connector from the exploded cap 😂

There may be a way to run Win95 using that 386 upgrade chip! If you can manage to track down an "AST Advantage 202051" ISA card, it can add an additional 3MB of memory! I used to have one when I was a kid (30 years ago). My dad's work retired one, and he managed to bring it home for me to play with on our old 286. It was amazing to watch my 286 slowly count all the way up to 4 megs of memory at boot-up. Wasn't good for much on a 286 though, as most programs that could make use of the extra memory also required a 386 processor or better. I had bought a copy of Mortal Kombat for PC, but it refused to run because of the 286 processor. I had always wondered if getting one of those 386 (or the Make-It-486) upgrade chips would've made a difference.

3:30 THE TOWER OF POWER!

Heya. Welcome back, Another quality video!

I remember my dad replaced our 286 with a DIY 386 back then (granted, I messed up the 286's harddrive with a speaker magnet) that he upgraded all the way up to it being a Pentium... Overdrive probably. This was the coolest thing for me when I was young, that said it's sad your chip sandwich does not work as intended.

4:43 Aah the old xt power supplies, common ground is superbound, common red is dead. I will never forget this sentence. Great upgrade options, i think those are quite rare nowadays.

VERY nice video! I have always had a soft spot for these 286s and upgrades ever since I worked with/on them in Berlin in the early 1990s. Your channel is impressive.

I like your style "Get the proper tool", proceeds to use anything in hand to do the job. Very old school and informative. You are cool. Hope someone replies about how to fix the cache thing tho 😅

thanks for this upgrade . perfect experience

As i remember, 80386 was supporting protected mode and also 32 bits registers, and SX suffix was about memory fetching against DX, but 80286 was partially supporting protected mode, and only for 24 bit registers, like interrupt description table registers, which actually were working in real mode with LIDT/LGDT instructions, and were really useful to redirect all interrupts to own table, thats was wonderful. But as 80386 became, you could control everything and create a VM in todays meaning. So it's more just an extension to technology, than clocks per instruction improvement, however speedup-up was also valuable, but probably due to higher frequency.

Amaizing stuff

I upgraded an IBM XT to a 486 via a 286 upgrade card. I then upgraded the 286 to a 486 slc chip. Was nowhere near the speed of even a true 486 SX system, but a LOT faster than the original 8088.

So glad you’re back, my friend! This was a fantastic video and I’m super interested in the 386 upgrade. Why would any user ever purchase something that only enabled 386 protected mode? How strange! It’s a shame about that cache module not working, but I hope you can figure it out; if anyone can, I know it’s you!

Cool I used to have a 26 when I was younger I looked at the BIOS you had I think I had the same functions that was somewhat 30 years ago and it was still interesting to go back and look at this older machine I still have my 286 motherboard I must see I miss the old days of the 286 386 CPUs this is where technology was starting to open up this was the beginning of things going much faster I have seen this technology evolve and I'm still amazed at the calculations some of these machines can still do if you would have to do all this calculation VI pen and paper it would take us so much longer however thank you for the video it brings back memories

I love the idea of running advanced tech alongside older tech. I am currently building a fast 486 build just so I can mix PCI, VLB, ISA, POD83 and 5x86s alongside each other in different configurations.

I'm glad someone found a use for all those trays of smt mount i386's. If I remember correctly they were still heavily used on some industrial embedded stuff (i presume medical related stuff they didnt want to rewrite from scratch) hence their really late manufacturings. Pretty cool!

Very cool parts! Would be really interesting to see that cache thing running. But nice to see, that my guess about the 386sx yesterday in the pre-announcement wasn't wrong ;) This were similar results, as what I got in the past. 286 is always slightly faster at the same frequency, then a 386sx. However, with 386sx you get huge benefit in Win3.11, since 386 has better support for protected mode and even more important VM86, which allowed to run more than one real mode program in windows in parallel. With 286, windows had to be closed during the execution of a real mode applications and was restarted again, when this application was finished. Thank you very much. I'll ask around, if someone knows anything about that cached 286 thing.....

The 386 SX 16 upgrade PCB you showed came on my old Wang desktop I had as a kid. I am not sure if it was made for those but it definitely had that installed.

As always, fascinating. It may be the chipset just not knowing what to do with the 386. I feel that there is a solution to be had and Mr Black make some brilliant observations. :-)

Upgrades components was very strange at the time ! Interesting video !

The Intel 80286 was an amazing chip.

Great video man, we've been missing you. Very strange that the upgrades had no effect. Could it be that maybe the CPUs were made for specific motherboards that support them officialy? Nice ending with Hexagon there, I played a lot of that game haha. Thanks again and have a great weekend!

It''s quite funny seeing your AT power connector still bearing the marks from when that capacitor blew up on camera ;)

Hmm, I wonder if a 486SLC would boot if it was transplanted to that 386 adapter.

omg that new intro is fakin wonderfull

In the early 90's I used similar parts from Kingston in order to upgrade IBM PS/2-30 ( 286@16MHz ) into ( 386SX @ 25MHz or 33MHz - I don't recall the speed exactly ). The Kingston daughter-board even had a socket for a 387SX math co-processor and the kit came with a replacement bios-chip.

I object to not adding Piccard when you dropped the part at minute 3 and a bit - thank you for the cool video

Welcome back.

In the early 90s, I do remember coming across a few IBM PS/2s ... can't remember the model, but they were one of the ones that originally came with a socketed 286. It had a 386sx daughterboard in place of the 286. It looked very similar to that first one you showed.

That is one amazing chip sandwich.

Very nice ! For the cache adapter, maybe it's possible to retro-engineer it using software in some way ? Don't quote me on that but maybe you can use a software to "sniff" the ports on the bus and therefore find those used by the adapter board ? (then you'll have to try many things to figure it out but anyways).

As i suspected, 386SX brings nothing performance-wise. As for that cache board - if RAM runs at 12Mhz with 0 wait states, than cache can not possibly do anything more. The only reason why cache is installed is that it runs at higher speed and lower latency than system RAM. If RAM already runs at CPU speed with zero latency, there is nothing you could do to speed the transfer up with caching.

That is a really nice motherboard. Plus cache if king too. I remember purchasing a p60 on clear out and loading up the board with either 1 meg of catch or 512. Anyway what a little speed demon. In some area it out performed a p75 and the horrible cache on a stick.

alright :) now lets do this the otherway around ;) squeeze a 286 cpu into a 386 board :) i totally expected that 386 being used through the cache improved adaptor. glad you are back :)

4:27 that cpu insertion sound is so nice

I have a similar little 386 board installed into the 286 socket on my IBM 5170. It's called the "Intel SnapIn 386" but mine has a 2.5x clock multiplier and 16kb cache right on the upgrade board. The multiplier is always active but the cache gets enabled by software - and even with the 20MHz clock speed, most benchmarks show slightly less performance than I got with the original 8MHz 286 if the cache is not enabled! Really goes to show how badly the 386 CPU is hampered by the slow memory pathway on this board (main RAM tests at at roughly 2MB/sec whereas the 16kb cache does about 10MB/sec). I wish I could mod it to have, like, 1MB of cache onboard!!

Awesome

maybe those cypress memories are not a cache, but, just some faster direct mapped memory, probably used by special sw that put critical code and data that needed to run as fast as possible.

Can u put the 386 board into the cache board?

I skipped from an 8088 to a 386, so I never encountered anything like this. Wow! That's so interesting.. i was cringing when you put the AMD chip in knowing how they have to be carefully removed (i guess i broke a socket like that in the past)..

They really sold some strange parts back in the days. I started with a 286 at 12mhz, then I asked for an upgrade, and they told me I need a different mainboard for the 386, but they have a cheap one that works perfectly for me (I was a student back then) and they take the other parts in commission for me. I trusted them and was not disappointed. After upgrading to an 386 with mindblowingly 33mhz, it ran like warp speed for me. And the best thing: The mainboard was somehow compatible to the 486 which I put in 2 years later (1995) and sold the 386 again. Now I had a 486DX2 80mhz and again, 2 years later I upgraded to a DX4 from AMD with 120mhz and overclocked it to 133mhz, so my 3DFX Voodoo card had something to do :D Such good times.

286 to 386:I'm a cybernetic organisms. Living tissue over a metal endoskeleton 💪

Ouch, thats a tower of power!

So nice. A serious looking "upgrades" that turn out to be downgrades. Also... i like burn marks on your psu plugs

Seeing Win95 running on a 286 board would be pretty damn interesting. :)

I almost forgot about that game!

I guess the only reason would be some Netware or UNIX that needed a 386 for memory management. Either way, intresting video. Would also like to see the "386 on the cache stack" and/or a crystal replacent to get it up to 16Mhz.

The 386 upgrade probably came from Improve Technologies or a company like them. In the 90s they made a lot of those.

At first glance I thought that 386SX upgrade might have been a Kingston SX Now, but after a quick google it looks much simpler, which is probably why it was no benefit. One of my IBM Model 50s came with a 386SX-20 upgrade boardr, which is also a lot more complex, including a few larger support chips and an 8K SRAM. Although it is a single 8-bit SRAM chip, so it would take a minimum of two clock cycles to retrieve any data, since the 386SX and 286 uses a 16-bit data bus. Unless it's doing some weird clock multiplying, but I feel like that would be way too complex for such a small upgrade board.

As others have mentioned the 186 and 286 execute instructions faster clock for clock.. The 386 advantages were in 32bit instruction set which hardly anything used at the time. A flat virtual memory addressing mode used by windows. The next intel processor with this slower next gen. The 486 is faster than the first Pentiums.. Pentiums had far higher clocked versions. Another fun fact about the early 486s is that for some applications it ran faster on un-cached motherboards because the super fast 486 burst mode 128 bit memory read. If your program read through data linearly the 486 could read effectively at 1/4 wait state. So for example if you are calculating inner products to multiply matrices you could exploit this quirk. Later higher clocked 486s always preferred a cache.

I'm guessing at 12MHz the ram is running at system speed with no wait state? Hence the cache would have no effect and might have been working all along.

Could you try making some DOS tests with a Transmeta Crusoe with adaptative instructions? I really appreciate your channel!

IIRC, the cache in these upgrade chips sometimes required a BIOS update to enable the cache. Which, as it turned out, was not always available for specific motherboards. There were compatibility issues. The only real advantage to the 286-to-386 thing was it gave you 386 enhanced mode for Windows, which was not available for 286-class machines. As for the memory limitation, there were peripheral cards that allowed more addressable memory. Four- and eight-meg cards were easy enough to find (but expen$ive!) So, in many cases, it was often more cost-effective (long-term) to spring for a new machine than to 'upgrade' what you had.

From what I remember, in practical terms the 386SX was nothing more than a 286 that could run 386 code and its main advantage was being able to run at higher clock speeds (than 286). For most hobbyists and enthusiasts, it was actually cheaper to just replace the motherboard/CPU. Those CPU upgrades only made (some) sense for proprietary/business systems.

I feel like the 386 adaptor was made for upgrading some machine tool equipment. Maybe some upgrade offered by a company to run their newer software with just a plug and play hardware upgrade. I don't know honestly. You just get these feelings when working on those old types of machinery. Such as getting a 486 based press brake running in 2021 and seeing the mixture of upgrades and repairs that have happened over its life.

Both of these adapters are things I've been trying to buy for a long time! Super super rare stuff. The cache is probably working fine, but is mostly there to compensate for slow 286 bus access to very slow DRAMs at probably 150ns. Might work better if not for using faster modern memory. I'd expect a tiny boost despite that, though, so maybe there is some software involved. The 386 will have worse performance per clock because of it's strangled bus, which means to do the same amount of work it must also take twice as many memory fetch cycles. Disappointed you didn't combine the 386SX with the cache shim! It has a higher chance of actually having a benefit.

I used to like playing HEXX and supaplex on an old system.

Lets put 386 OverDrive into 386 to 286 adapter, so we run 468 while running like 386 on 286 board!

Would love to see if you can track down one of ImproveIt Technology's "Make-It 486" chips that supposedly upgrades a lowly 286.

Maybe not time to give up on the cache module just yet. Perhaps those 100ns drams are being run at 0ws anyway (83ns) As I was able to use 100ns Ram in a little project I had going that required 80ns back in the day. Would be interesting to try on 20Mhz 286. A speed where the 100ns DRAMS will definitely not go. If it still doesn't gain performance, then I agree the 6k cache is dead. As for the 386sx being slower, I remember my 1st upgrade was from a 286-16Mhz to a 16Mhz 386, and it was a massive disappointment. If anything it seemed a little slower. HOWEVER, whereas my 286-16Mhz was unstable overclocked at 20Mhz. My lovely 386sx cpu would over clock to 25Mhz. At which point it was a big improvement after all :) Plus it ran windows3 properly :)

It was known that 286 was clock for clock faster than 386sx. That's why 286 with Harris 20 or even 25 Mhz PC still sold long after introduction of 386.

Very cool video! It's not surprising that the 386sx performs similar/worse than the 286, the bus drivers would slow it's ability to interact with the bus slightly. Unlike other steps in CPU generation the 386 actually has a similar IPC to the 286, with some instructions being faster on the 286 and vice versa. For 16bit software in general 386 and 286 systems of the same clock speed are generally roughly equivalent. Even proper 32bit 386 machines are similar in IPC, the main speed difference being they can fetch instructions faster. What differentiates most systems of this period is actually the mainboard, memory and graphic card. A chipset with cache, faster RAM, or a faster graphic card makes a far greater performance difference than the CPU given the same CPU clock speed. The only way to make the best use of these upgrades is to have the software for the cache, or slightly increase the clock speed on the board for the 386 (it can do 16Mhz).

After seeing the video, think you missed some jumpers to increase the clock accordingly to the processor. Also, the big justification to use 386 instead of 286, is the 386 can run workgroups and is network compatible who is not with the 286. I still use a 386DX40 with a stepper isa board to control an OZO PCB prototyping router/etcher/driller/ for manufacturing Motherboards in 1987. I have a 286 Zenith working but not network. The 386 is a slave of a win7 to transfer the Gcode to control the OZO (jot) unit.

I have one of these. It sits snugly in my PC9801VX. I actually plan to replace the 386sx16 CPU (Clocked at 20Mhz) to a 486sxl2 CPU at 40Mhz.

Could you put the 386 adapter in the cache adapter? For science?

Any chance of enabling the cache and re-running the benchmarks?

there were some pretty good snap on 286 upgrades (less of a gimmick) made by IO DATA for PC9800 - by the nature of the architecture, most are compatible.

Just started watching. I'm *thinking* the 386SX plugged into a 286 board won't really be any faster on 16-bit code; except that a 386SX can clock higher than a 286 if both are OC'd. I look forward to seeing the results :)

I got one of these in an NEC Mate 1 PC I saved while dumpster diving. I still haven't had the time to restore it yet.

I really hope to see the cash working

My friend had a 286 motherboard which had 20mHz cpu and 1mb of very slow RAM soldered on mb and no simms. But this motherboard had 64kb of cache! And in Norton SystemInfo this board(cpu) scored 15.9 instead of usual 15.0 for 20mHz.

The one that has the Intel 386SX looks like a Kingston brand. I had a similar one but wasn't the PLC socket type.

Even if a 386 upgrade is slow, it's still better than adding cache to a 286. They both make the system faster, but cache doesn't allow you to run 386 software, so the extra functionality makes it worth it. If you don't plan to use your system to run 386 software, like, if you have a 386 system for that already, then go with the cache.

Cyrix has a utility to active Cache in the operating system. May be worth a try. You'll also need to upgrade the crystal. While you would be over clocking the ISA slots, you might be able to get away with it, since most of those slots will work at a faster speed. I've heard the a clock for clock cycle between the 286 and 386, the 286 is actually faster. You have to get a fast clock speed to gain the benefit. Hope that helps.

Could you change the motherboard oscillator to increase the mhz to 16?

Pretty sure someboby wrote it already in the comments, but oh well, combine the 386 upgrade modul with the cach module and run your software to test if this cache is even recognized.

Have you tried stacking the 286 cache pass through board, with a 386 CPU to 286 M/B adapter?

Thus was before my time

The socket sandwich is pretty ridiculous to see, too bad the cache upgrade did not engage. I'll hope you'll get more info on these thing, it's pretty intriguing stuff.

Yeah - at 6:34 your PLCC socket is cracked. The sockets weren't designed for many insertions/extractions - I cracked the sockets on a couple of PS/2 Model 50Z planars testing the Kingston "386 Now!" upgrades.

Is there any way to adapt one of those SX2's into this board?

What about putting the 386 to 486 clip-on on top of the 386 adaptor? It will probably not work, but hey, it's to exciting not to try!

Would you have any 286 chips in a CLCC package? I remember one which was made by Siemens.

Your BIOS has a "Scratch RAM option" could this be cache related? Or is it some onboard scratch RAM on the board?

Leider habe Ich keine Ahnung aber hoffentlich geht's alles gut bei Euch ciao Magister

Any idea where I can find a 286 machine running at 8MHz? Sounds odd but I have old software that can ONLY RUN on this old platform and speed.

I have a 286 to 486 upgrade that's pga... Think it work on a 386sx motherboard if I change the socket? It's plcc