I dont have the answer to any of your questions but I have to comment and say those are 2 beauties!

Excellent finds and I hope you enjoy them

Both of those look to be excellent specimens, and yes I'm jealous!

Killer haul! Congratulations. I really love the look of that first case. Very lucky! 😀

Dochartaigh wrote on 2020-03-05, 21:51:

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MMX 200MHz:

IMGUR PHOTO ALBUM: https://imgur.com/a/0LNCcYO

Generic? Beige case w/ Turbo buttonTopgun/Alton M575 Socket 7 motherboard

Alton = PC Chips. Look for M575, lots of info. "TXPro" is actually ALi Aladdin IV, one of the best non "super" So7 chipsets. Wafer-thin board though, watch for bad caps.

Intel Pentium MMX 200MHz, SL2RY, 66mhz bus, SPGA Socket 7
128mb RAM (what type do these use?)

EDO or SDRAM. SDRAM is faster.

Trident 3dImage 9750 VGA Card (how much RAM?)

Chip codes aren't clear, but it looks like 32Mb = 4MB per chip, so 8MB total. This is a slow Trident chip, so don't expect much from that RAM. 2D Windows desktop at 1024x768@full colour is great, but not really a game thing.

Built-in Sound

Nice one - C-Media CMI8330. ISA, SBPro2 and SB16 support. No significant bugs. No real OPL3, but close enough for most purposes (better than CQM)

The Turbo button doesn't turn the light on or off – should I check the wire running off the MB? Or does the MB and/or CPU need t […]
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The Turbo button doesn't turn the light on or off – should I check the wire running off the MB? Or does the MB and/or CPU need to support this feature and this one might not?

How is this motherboard, do people like it? I need to move all the cables off to the side but is this era the ones where the cache for the CPU is on the MB itself? Is that something you can upgrade? 

I'm not familiar with the Trident video card - will it be OK for DOS games? If not, what would people suggest for a PCI video card? My knowledge only really starts around the TNT2 era...

Disappointing this has built-in sound, but it has plenty of ISA slots I can populate (that's another thing to research - currently have an ESS ES1869F)

Not disappointing at all, this is like ES1869F with SB16 support added. No need to populate it with anything else unless you want exotic stuff.

486DX4 100MHz:

CRM Beige Case with LED MHz display
UNKNOWN Socket 3 motherboard (board marked "V3.4B/F", largest chip: UMC UM8881F 9652-EYA MB1226)

Also PC Chips, M919

Intel 486DX4 100MHz, SK050, 33mhz bus, multiplier 3, CPGA
32mb RAM
Trident Pro Vidia 9685 (where these all 2mb?)

No idea, looks like 4MB actually - those are 256kx16 chips, so 4Mb. 8 of them makes 4MB.

Sound Blaster 16 CT1740 w/ manual volume dial (never seen one of these!)

1st gen sB16. Relatively few bugs but noisy as hell.

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The real gem of this in my eyes (well, besides these being brand spankin new - and yes, I asked him if he still had the boxes and he threw them all out!!! ;( is how this has a REAL Sound Blaster 16 in it - complete with a manual volume dial! It's marked model CT1740 on the sticker on the back. Biggest chip is CT1746B; also has CT1748, CT1745A, CT1741, CT1701, and Yamaha YMF-262 chips. The CT1741 being v405 means this does NOT have the hanging note bug, right? And the Yamaha 262 means it has real OPL3 sound? There's a million versions of these cards so that's why I mentioned all the chips I noticed + detailed pics.

Meh, "real" SB is overrated. They tend to be buggy and/or noisy. This one is refreshingly bug-free, but totally unshielded so noisy. If your system is quiet in the audible range it will sound good, otherwise you will hear everything.

Video card - is this crappy, or just how they were back then? 1024x764 24-bit (no 32?) gets a funky pattern. 800x600 24-bit is fine. 16-bit has a pretty crappy range of colors and I normally run on 1024...

This is one of the later Trident models. Not a high performer, but the most trouble-free TV-out I've ever seen. On a 486 under DOS it really is pretty irrelevant, bus performance is far more important than what the card does.

Oh, NEITHER of these processors have thermal paste on them. Should I peel off all the stickers and add some? I have Arctic Silver Ceramique 2 (also have ARCTIC MX-4 I haven't used before if that's better).

Look up what the TDP of a 486/P55C is. They don't need the paste.

The Trident boards are never going to be anyone's favorite, but they'll do. Run what you've got and replace what doesn't work for you when it becomes obvious that a particular component is holding you back. In the meantime, just enjoy it.

Regarding your video mode problems, are you 100% certain you have the right driver? If you just downloaded something (vs. having the original disk that came with it), there's a good chance it's only mostly compatible. Back in the ISA/VLB days, there was no definitive way of detecting a graphics card like you can with PCI IDs. All you could do was poke at it and maybe the chipset would have a few magic registers that would provide something positive. But, the board itself was often manufactured by a fly-by-night company, and who even knows how they implemented it.

The other possibility could be a video RAM mismatch. 1024x768 @ 24-bit color requires a lot of frame buffer memory. 486-era boards do not guarantee that. 1024x768 @ 256 colors was pretty typical for a mid-range board. Graphics professionals might spring for a 4MB+ board, but most of us poor saps had anywhere from 512K to 2MB. True color at 1024x768 requires 2,359,296 bytes of video memory.

There was a recent post that had a chart of which SB cards had which flaws. If you care enough, that info is well documented here. IMO, forums like these -- with enthusiasts that have higher than average technical expertise -- tend to get hung-up on issues that aren't really that important. *IF* you're one of those who is using a certain game using both PCM and an external MIDI synth at the same time, you might run into a bug. Again, rather than spending your time fretting about it, play a game. If it exhibits the flaw, then maybe do something about it. In the meantime, it's probably not worth your attention. Don't let the "perfect Sound Blaster" frenzy sweep you up into its madness, it's just obsession run amok.

damn thats an amazing find

If you find that the CT1740 is too noisy, you can just disable the internal amplifier by moving OPSL and OPSR jumpers to the 1-2 position, I suppose you'll be using amplified speakers anyway. Unfortunately earlier cards such as the Pro do not allow the possibility of disabling the amplifier, so you can get lots of "system thinking" noise.

that first case is an absolute beauty :3c

congrats

There was a Craigslist ad in my area recently for that first computer with the monitor you mentioned for the price you mentioned, so either it's a complete coincidence or I have competition around here... 😜

some good solid AT (not ATX) builds... and great looking/good condition too. You have some pretty run of the mill hardware (not in a bad way), and a good foundation to build/tinker from. good find!

I'll reply to everyones posts tomorrow - but what's the word with mice for these? I can't deal with the roller-ball non-optical mice (they don't play nice with my furniture and I really don't want to get a mouse pad).

Reviews on PS/2 to 9-pin Serial adapters say they don't work on 486 computers? And the only other option is an add-on board (or a DIY electronics project)? I have 3x Microsoft Optical mice (from the basic model to intellimouse explorer 3.0). All are either PS/2 or have a USB to PS/2 adapter. These computers only have the 9-pin DB9? port.

The case with the 200MMX I'm a almost certain has been designed for earlier generation hardware, giving the turbo button and the 5.25" drive. Which were both no longer common at the MMX era. Looks great, though!

Dochartaigh wrote on 2020-03-06, 03:16:

I'll reply to everyones posts tomorrow - but what's the word with mice for these? I can't deal with the roller-ball non-optical mice (they don't play nice with my furniture and I really don't want to get a mouse pad).

Reviews on PS/2 to 9-pin Serial adapters say they don't work on 486 computers? And the only other option is an add-on board (or a DIY electronics project)? I have 3x Microsoft Optical mice (from the basic model to intellimouse explorer 3.0). All are either PS/2 or have a USB to PS/2 adapter. These computers only have the 9-pin DB9? port.

The M575 has a PS/2 header next to the AT connector. If you can find a matching port you can just plug it in, otherwise you need to modify pinout, but still pretty trivial.

As for serial to PS/2, there's a lot of blind leading the blind misinformation out there. Serial is basically serial, it works or it doesn't regardless of PC age. What does differ is what the PS/2 devices actually do. To work with a passive adapter the device actually needs to be able to talk serial. Some do, most don't. Same with USB-PS/2 adapters incidentally, which is why it's pretty much impossible to get a USB device working with serial via two adapters.

I've been looking at making my own active PS/2 to serial adapter with an arduino. Should be possible but I've not gotten it working yet. Best option if you don't want that level of work is to buy a serial optical mouse. They exist and can be found on eBay for somewhat acceptable prices. Note that you *don't* want a vintage Mouse Systems optical as they only work on a metallic mouse mat with grid lines. I love them, but if you don't want the mouse mat, they are not what you need.

Dochartaigh wrote on 2020-03-05, 21:51:

CRM Beige Case with LED MHz display
UNKNOWN Socket 3 motherboard (board marked "V3.4B/F", largest chip: UMC UM8881F 9652-EYA MB1226)

Yes, this is most probably M919 motherboard. I actually really like it as it has ISA, PCI and VLB slots and it's fast too. The most problematic is cache. It uses cache-on-a-stick and usually it's missing....

PS/2 to Microsoft Serialmouse Adapter Converter / Updated First Post / Firmware Update added

Code is on Github.
maybe this item is listed soon on Serdashop to.
small bugs are currently being ruled out.

I've been looking at making my own active PS/2 to serial adapter with an arduino. Should be possible but I've not gotten it working yet. Best option if you don't want that level of work is to buy a serial optical mouse. They exist and can be found on eBay for somewhat acceptable prices. Note that you *don't* want a vintage Mouse Systems optical as they only work on a metallic mouse mat with grid lines. I love them, but if you don't want the mouse mat, they are not what you need.

You scored! Beautiful machines - they look good as new! People say good things about the first case, but the second one looks great too imo. As someone that just got back into retro hardware and who is actively looking around for old computers to give a second life to, I can only dream of scoring something like this.

I've been looking at 486DX2 66MHz's on eBay, and this is the next newer version of it, right? Can I upgrade the processor to a little faster?

As I've been told by other members here, if you want max compatibility with the whole DOS era, you should actually look for a slower CPU, ideally a 486DX-33 😀 with the turbo button + cache disabling you should be able to get to real slow territory without the need for CPU slowing tools (moslo etc..). In addition to your P200 and P3-700, you'd have a pretty nice lineup that should cover most games.

Have fun with the new toys!

Woah, do i see it correctly? A socket 3 motherboard with COAST module? 😮

Dochartaigh wrote on 2020-03-06, 03:16:

I'll reply to everyones posts tomorrow - but what's the word with mice for these? I can't deal with the roller-ball non-optical mice (they don't play nice with my furniture and I really don't want to get a mouse pad).

Reviews on PS/2 to 9-pin Serial adapters say they don't work on 486 computers? And the only other option is an add-on board (or a DIY electronics project)? I have 3x Microsoft Optical mice (from the basic model to intellimouse explorer 3.0). All are either PS/2 or have a USB to PS/2 adapter. These computers only have the 9-pin DB9? port.

your Pentium system already has a PS/2 port on the back of the case - it's the 6 pin mini-DIN that looks like svideo but is next to the DB-25 parallel port

ps/2 optical mice are available, or you can convert many older USB optical mice back to ps/2 with a passive adapter