I got one back in 95 and recently rescued it from my mother's attic. The battery damage destroyed many SMD components. Thank you for posting this video. I'm hoping I can repair it one day once I've gotten confident with SMD soldering.
Great video! My Dad bought a Macintosh 512K back in 1988, and there were some games that I loved playing on it that I’ve been told will work on the Macintosh Classic, but not the Classic II. Beyond Dark Castle, Arkanoid, Sim City, were all Mac games that I had a lot of fun playing.
Could be. The cache result being lower is odd but it could be a rare situation where cache gets in the way of an already difficult situation for the processor.
hey! a bit late, but I got the same problem but i had 3 bars on the screen. my logic board has 4 ROMs. I recapped all the logic board caps but i STILL have the same problem. I tried to use new RAMs, new batteries etc. but still no changes. any ideas?
@@DKJones96thanks for the reply. i cleaned it 2 times with circuit cleaner sprays, and i did new solders for the analog board because there was arcing issues. its kinda fixed but i still have problems. when i turn the machine on, the bars show up. i wait 15 seconds, it returns back to normal. sometimes no image, sometime just straight up works. i found out that playing with the ports in the back can remove the image or make the machine work like normal. i inspected the ports but there is no damage to be seen.
@@uni2nd The place to look for damage would be around the square cheap near the audio jacks. That's the chip responsible for CPU reset and sound and if it has a bad trace it could be causing an issue. There should also be a couple of buttons, one of which is reset, and traces from that being messed up could cause this too. It sounds like it is probably clean enough.
Definitely a good idea! At minimum you want to test it without the computer but I do find that catastrophic failures on the old AT stuff isn't all that common.
Hello.can I upgrade the i386sx-20 mhz CPU...to an am386sx-40?are the pin compatible an voltage...thank you.i know it will still work at 20mhz...but will it work?thank tou
You can 'upgrade' to that processor but as you said it'll still only run 20mhz unless you up the bus speed. Is there a particular reason you are looking to make that change?
Might as well replace the varistor(s) while you are in there as they wear out too, and are quite cheap, just make sure you get the exact same value. Every spike they absorb wears them out a bit, so might be the first component to wear out.
I have the same DayStar PPC card, but I get an error whenever I try to boot using the 601 Processor Upgrade control panel. It chimes correctly, but leads to a "DUN DUN DUN" error sound with a Sad Mac. Have any suggestions on troubleshooting?
So sorry for the late reply! No idea why I didn't get a notification for this post! Do you have a universal installation of Mac OS? It needs the 'for all macintosh computers' version installed because of the PPC vs 68K stuff. Another thing to try could be carefully removing the cache card.
Hi K2, I'm currently working on modding a board very similar to the one in this video. Mine maybe a knockoff of your board. I wondered: Is your board a 2 layer board as well? Mine is, which is of course not ideal for overclocking and such. Boards like these can look the same from a distance.. Mine is very similar to yours and features the exact same components but it's a 2 layered Gemlight GMB-386SAT. Thanks in advance!
It is a 2-layer board. It seems to handle 50MHz without issue. I can't tell you how it handles anything faster but you'll start running into ISA speed issues above that as well. I wouldn't be surprised if there were only a couple different places making these boards as late as they are in the game. That Gemlight does look very similar and I have seen a few others that look similar as well. Maybe a bios chip moved around or something.
@@DKJones96 Thanks! The Gemlight may be a rebrand of some kind or the other way around but it's good to know that it can handle 50MHz as I'm going to solder on a SXLC2-50 with a VREG and I'm going to try running that at 0WS using 45ns memory (I just did some shopping @Atheatos ;-) ) My build is going to be a crossover between your two builds. He had the misfortune of having the sleazy SARC/PCChips chipset ;-) I have one of those boards as well but mine even refused to run faster than 30MHz!
It does apply a load but it is so miniscule compared to the output of the power supply that it might as well be non-existent. The supply should source an amp or more and the 10 meg-ohm input impedance of the meter will only take a few nanoamps. Now, if we were talking about a sensitive amplifier with meg-ohm resistors in it then yes, it would matter.
hello I have a machingtosh clasic 2 with the same problem and Im wondering what will hapen if you just take of the capastioors and start it. i dont reely have the monny to buy new ones 🫤. or if you can just put in idont know random capsitors?
Negative on all accounts. It requires the caps to run, that's part of why when you get leaks you end up with the checkerboard screen. You might be able to get away with assorted values but I would be very careful here. You need to have at least the factory cap's rated voltage and I wouldn't more than double what is there. For example, a 10uF 6.3V cap could be replaced by a 22uF 25V cap, though that likely won't fit in the same spot unless you are going to tag on through hole parts. That will work but you risk accidentally ripping off pads if you pull the cap too hard.
Hi there and happy holidays! I really enjoy your videos about 386SX boards, as they're kinda my passion also. Your SX25 w/64k is an absolute monster and a great find! I do have a 'newer' 386SX with cache -- a DataExpert based on OPTi 291 chipset from ~1993, and it's the size of a typical late 386 board, actually. I tested it on my channel against the 486SLC2-50 and I found out it's ridiculously quick -- actually a lot faster than my SLC board in many cases. P.S. Will you swap the CPU and the clocker for the 40MHz and see what it does then? I doubt this relic will ever work with the 486SLC/SXLC... P.P.S. Such an unusual BIOS shell! Then again, I've never really played with <1992 boards
I'm going to guess that you are going to try and replace the 25MHz processor with a 40MHz one. That will require you to update the clock oscillator chip as well. Then I would also guess that you will had a math-coprocessor to it. Interestingly I have a baby AT 386DX-40 motherboard that has cache on it as well. It has 64KB installed, but the manual says it supports up to 128KB. I have it set up as my 'needs to be slower than a 486, but faster than an 8086' machine. It works quite the treat. I have a Sound Blaster Pro 1.0 in it and a MPU-401 IPC-T card. Video is a simple Cirrus Logic CL-GD5429 with 1MB of ram. Still waiting to get my hands on a Tseng Labs ET4000 card...
The Tseng is of course a good card but I think it tends to be a bit on the expensive side because of the "lore" ;-) There are other ISA cards out there that are on par if not better than the ET-4000.. This surprised me a lot but a Trident TVGA 8900D is actually faster in 0WS mode and also features memory interleaving! The Western Digital Paradise WD90C31, like you find on the Diamond Speedstar 24x is also marginally faster than the Tseng as is of course the Cirrus 5434 like you would find on the Diamond Speedstar 64 but those cards are insanely expensive. I'd say the Trident TVGA8900D is the best bang for your buck as a lot of people tend to hate the brand, making them relatively cheap while this particular card is actually blazing fast for an ISA card ;-) This surprised me as well but I have them all and the Trident is surprisingly good. Of course the Speedstar 64 (CL-GD5434) with its 64-bit memory bus and 2 megs of VRAM is the pinnacle card because of its speed, display quality and special features, but prices are pretty insane...
You can potentially go both ways with this board, both would be very interesting. You could push it up to 40+MHz on cpu/bus. Maybe even go with some 486slc. I have a 386dx40@45 myself. But because 386sx boards are basically 286 boards with 386 CPUs, it would be very interesting to see a 286 with external cache! It might just be possible... NB! Don't care about the giveaway, but the topic is interesting!
Hmm, A 286 with cache is an interesting prospect! Another user has said they did have a 286 board with cache. I feel I have enough platforms and boards to mess with so I don't think I'll be shopping for that but yeah, they did apparently exist!
Yes, the on-board motherboard cache is L1 for the 386SX, however, it's much more difficult to try and get across the differences between them and talk about them that way. Defaulting the motherboard cache as L2 makes it easier to convey that there is a difference without having to denote external and internal cache. Just saying 64K L1 still losing vs 1K L1 can get confusing while just calling the 64K L2 almost automatically conveys an external cache. On the DX platform, where most have cache, it's easier to just always call the motherboard cache L2 instead of renaming it between having a 386DX installed vs a 486DLC. Of course, this is all my opinion but it's why I do refer to it as L2. Especially since this is going to open us up to DX platform comparisons.
You can upgrade directly to 486slc. The ultimate upgrade for this M/B is to put an 486sxlc2. This is for sure and 3.6v chip so you need an adapter or to lift the VDD pins and connect with wire to a voltage regulator. In either case you have to check if the flush pin is connected, if not you have to add extra circuit there for that. Finally for clock generator the best is to replace the oscillator with my any_clk device.
@atheatos nope and nope Just fyi there are 2 16/32 bit 16 bit is the BLC/2-3 and the 32bit BLX which goes to 4 100mhz all are easy to get if you know how to look I'll give you a hint JAPAN
I have a few already. For sure quite hard to find get out of Japan. I have never seen someone successfully 100% molding one on a 386sx PC M/B. Nor I have seen a datasheet with the pinout of the chips. If you have DOCs like that please send me :). I want to try modding.
thanks for sharing, i only have dx systems with caches. Maybe you can add more cache, reminds me of a 486 board that could be increased with an additional address line soldered to the extra pin.
The manual I have for the chipset says up to 256K cache supported so this is a distinct possibility if we are shooting for the fastest possible SX platform!
Hi, would you like to share this motherboard to theretroweb ? We don't have it properly documented yet :) I have an interesting VLSI based 386SX motherboard which runs a 386SX25 as well, but mine allows to put the waitstates down to zero, which makes my 386SX "insanely fast" (for what it is). I have an old benchmark I made over 6 years ago that says it scored 8.2FPS at the superscape benchmark, and I didn't even had a tseng labs video card. I think I can get an extra FPS with a tseng labs ET4000 card, but this will need more testing. Also I now have much better hardware to make footage (both to record live footage and also capture VGA), so I guess it should be a much cleaner video :D By the way it's a DataExpert VLSI SCAMP if you want to find what it looks like
I will have to look at how to upload to theretroweb. I found some data on stason under the Dash DC-386SX. It isn't perfect but it's really close. For the 9.9FPS result I had the ISA bus clocked to 12.5MHz and 0 wait states. I also played with disabling and enabling the cache on the fly but it doesn't work quite right when re-enabling it.
Thanks! I'm going to be 'improving it' in the next installment with a 3xAAA to 18650 adapter and an 18650 holder. It is smaller and more secure. This hasn't given me issues and I did transport it to a computer show last month without issue but I also want my crappy HFT UV light back.
Maybe overclocking to 33MHz and change the cache chips with faster ones? Or, even better, swap the CPU with a fastest one and also try to overclock it. I wonder what is the max speed of those OPTi chipset ICs. However, is nice to see this odd motherboard and the benchmarks. Is amazing how the L2 cache makes for a speed increase of 60% in that time when the aim was the fastest CPU speed.
Good guess but not what I have in mind. I will post what it is after someone guesses it. I think the only way to find out what the OPTi chips can do is to swap out some crystals. The datasheet only mentions up to 25MHz but since the fastest SX at the time of print was a 20MHz and 25MHz was an overclock recommendation for getting that speed it's possible it might run faster. I don't think 33MHz is out of the question for sure.
Oh please put a 486SLC on there, change the crystal and speed it up a bit, maybe the cache chips will need to be replaced for faster one, hard to tell. Not in for the giveaway, I just want to see what happens with 8K L1 and 64K L2 hehehehe
I had a 20 mhz 286 with 1 meg of slow (300ns) ram onboard (32 chips), but there was 64k cache and this MB performed better then 'normal' 20 mhz 286s in benchmarks.
Nice video! Personally I would forget about OS9 and put 10.4.11 on it if you’re using it as a daily. I just use 40GB WD drives in mine and find them more than adequate, but then I’m not a gamer! As far as the internal speakers go, no internal speakers are as good as a set of decent external speakers, I picked up a secondhand pair of Bose speakers and they sound 1000% better, so I just use a midrange speaker for the bubbles, just to say it works haha! But nice detailed video, you should try getting a tray loader , they’re another lot of fun to be had😂
I didn't feature it here but I do have an iSub that I use with this sometimes. Really helps fill out the sound! A tray loader with a Voodoo mezzanine card would be sweet.
There is a reason they use lithium batteries in modern electronics. They don't leak. If you're going to use that system make sure you install dry cell or lithium batteries. No retro Mac is complete without After Dark. That is the era where PC really started to surpass Mac. In the past Apple/Mac has been able to do more with less but PC software and hardware advancements took hold thanks to more opportunity.
The leaking thing is a great point. I do want to use lithium but I am having trouble finding something I am happy with. I'm thinking of going with two coin cells through a 1.5V zener diode to give me 4.5V. It's a bit wasteful but at least it won't leak like these AAA batteries eventually will. Any recommendations on this front? I also don't like the giant battery pack blocking the rear vent a bit which I honestly didn't think about until after I went to put the rear cover on it yesterday.
@@DKJones96 The apparatus you had will work. Just get some AAA lithium batteries. They have a shelf life of 10 years. Or use a lithium coin cell like the 3v CR2032 like modern PCs use. If 4.5 is what you need and you want to use button cells, use Silver Oxide. Has long shelf life and won't leak.
