VOGONS


The $10 486

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First post, by probnot

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Taking a break from the 286, I picked a couple of AT towers for $10 each (one 386, one 486). I decided to spend some time with the 486.

Bought these (retro) hardware today

- Unknown VLB Socket 3 motherboard
- 486DX2-66MHz CPU
- No RAM
- 3.5" Floppy drive
- Trident TGUI9440A VLB Graphics (1MB)
- VLB I/O Controller (with 2 IDE channels)
- ESS AudioDrive sound card
- Mustek GI1904A Handscanner Interface Card (a hint to what this machine used to do?)
- Old Modem (meh)

The inside looked ok, except for the CPU/heatsink/fan was just floating around the case, with some bent pins.
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The board is awesome. I think this is going to be my main 486 if all goes well. CR2032 battery holder, VLB. The only thing missing is a VRM, but that's ok, I didn't plan to go up to a DX4 anyway.
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It was also missing the RAM, so I had to go into my stash to see if I had some...turns out 80% of my stash is EDO...
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Power supply was disgusting, so that got a good cleaning with compressed air (as did everything else).
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One interesting thing about the CPU fan. When I pulled it off to clean it, I noticed it has two labels. It's either a 1W Topower brand, or a 0.9W WLS brand...
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Finally after trying another PSU, another CPU, and another video card, I realized that it's very picky with RAM. Out of all my sticks, it likes 4 of them (and 2 of them MUST be paired together). Oh well, one of the sticks it likes it 32MB!
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At this point, since the board was out I figured I would upgrade the cache (since I'm settling on 32MB RAM). It came with 128KB, and I got some extra chips included when I bought some RAM recently. So, 256KB it is!
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I really like this case. Unlike some of the similar cases I've seen, the motherboard tray is removable, not just riveted in place. I also had to add some (actually 4) missing plastic standoffs. The way this board was mounted, an entire corner could short to the case if you weren't careful
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At this point I started having a lot of post problems. It would seem to go dead if I left it sitting for a while. Removing the RAM or video card and booting it would cause a beep code. Then re-installing the RAM or video card, it would boot fine. This would work great until I left it sitting for a few minutes again. I tried replacing the CR2032 (even though the old one metered ok), tried another PSU again, tried the other sticks of memory and finally settled on replacing the video card after it booted once with signal to the monitor, but just a black screen.

This seems to have solved the problem (hopefully). It's running with a Triden 8900D ISA card (1MB) with no issues. I have a VLB Mach64 I'd like to try in this, so it's not the end of the world.

Any recommendations for this? I've never used an ESS card before, they any good? or should I throw in an SB16 or AWE64? For HDD I plan to use a CF-IDE adapter (I only have a 512MB card for now, need to source a larger one...these things are hard to find nowadays). I do plan on adding a CD-ROM, but it won't be period correct (I prefer functionality in that regard)

Reply 1 of 24, by LHN91

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From what I recall, the ESS cards have either an exact OPL3 clone or the ESSFM chip which I find actually sounds a bit richer than a real OPL3.

Reply 2 of 24, by gdjacobs

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probnot wrote:

I've never used an ESS card before, they any good?

Yes, they're very good. ESFM is, of course, not 100% OPL3 authentic, but I think it sounds fine, and the cards are otherwise drama free.

Unlike my CS4232 card which allegedly works in WSS mode... when it wants to.

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Reply 3 of 24, by probnot

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This computer is teasing me. It still sometimes doesn't post. But powering off, then a quick wiggle of the motherboard brings it up and stable every time 😒

Also, I think I'll keep the ESS installed, I want to hear how it sounds.

Reply 4 of 24, by appiah4

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probnot wrote:

This computer is teasing me. It still sometimes doesn't post. But powering off, then a quick wiggle of the motherboard brings it up and stable every time 😒

Also, I think I'll keep the ESS installed, I want to hear how it sounds.

Sounds like a cold solder somewhere or shrtinv against the case somehow?

Reply 5 of 24, by CkRtech

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probnot wrote:

This computer is teasing me. It still sometimes doesn't post. But powering off, then a quick wiggle of the motherboard brings it up and stable every time 😒

Are you sure the motherboard wiggle is directly related to it coming back up? A reset alone won't do it? Just wondering if it might be that power supply (which most likely needs a recap anyway).

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Reply 6 of 24, by probnot

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CkRtech wrote:
probnot wrote:

This computer is teasing me. It still sometimes doesn't post. But powering off, then a quick wiggle of the motherboard brings it up and stable every time 😒

Are you sure the motherboard wiggle is directly related to it coming back up? A reset alone won't do it? Just wondering if it might be that power supply (which most likely needs a recap anyway).

Definitely the wiggle. At first I thought it was reseating the ram or moving thr video card. Then i realized i could just pull the board out a little, let go, and power on with success.

Reset has never worked for this problem, and powering off and on doesn't either (I tried a bunch of times). But wiggling the board yields 100% success rate so far. I've tried another PSU (known good one) with the same results.

Next I'm going to try reseating all socketed chips,and swap out the CPU for another DX2-66.

Reply 7 of 24, by badmojo

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Yes the Audiodrives are usually very solid.

Regarding your post issue, I wonder if it does the same thing outside of the case? I.e with the motherboard just sitting on your desktop and powered up. I seem to remember having issues with a board once but only when mounted in the case.

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Reply 8 of 24, by probnot

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badmojo wrote:

Yes the Audiodrives are usually very solid.

Regarding your post issue, I wonder if it does the same thing outside of the case? I.e with the motherboard just sitting on your desktop and powered up. I seem to remember having issues with a board once but only when mounted in the case.

It was doing it outside the case too. I mounted it once I thought I had solved the problem with the video card. My worry is if it's a trace on the board, that would be hopeless... it could have to do with the lack of standoffs it was originally mounted with. Maybe it got bent or damaged or time?

Reply 10 of 24, by probnot

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CkRtech wrote:

Could you give us a photo of the bottom of your motherboard? Also - how do the solder joints for the power supply connector?

It's mounted in right now. I'll pull it apart this weekend. I went over the back of the board in the sunlight (incl. the power header) and didn't see anything. I'm still going to try reseating any socketed chips, just because it doesn't involve removing everything (also another CPU, since this one was seriously beat up with bent pins).

Reply 11 of 24, by probnot

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probnot wrote:
CkRtech wrote:

Could you give us a photo of the bottom of your motherboard? Also - how do the solder joints for the power supply connector?

It's mounted in right now. I'll pull it apart this weekend. I went over the back of the board in the sunlight (incl. the power header) and didn't see anything. I'm still going to try reseating any socketed chips, just because it doesn't involve removing everything (also another CPU, since this one was seriously beat up with bent pins).

Reseated the BIOS chip and it's been behaving well so far. I originally installed a rear mounted CF-IDE reader which worked great for a while, then just stopped reading the CF card. I swapped it to a different style, and everything is working again (nothing corrupted on the card). The rear mounted one didn't have a voltage selector, so I wonder if it's 3.3v and that may have caused an issue.
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Also replaced the (non-working) floppy drive and installed a nasty looking 52x CD-ROM (it's the best I have available right now).
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Sound card works great. Just lost a few hours in Warcraft2 campaigns (was only supposed to be a test). I also really like this BIOS!
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Side question, any way of finding out how much RAM a video card has? Is there a utility that can show this?

Reply 13 of 24, by probnot

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cj_reha wrote:

Regarding the utility, Speedsys will. But 99 percent of Vesa video cards are 1 mb, so unless it's been upgraded it's probably that.

So...wow. These results are crap, and kinda reflect the odd problems I've been having with this system. I tried swapped another DX2-66 CPU (AMD) with exactly the same results. It's like there's no L1 cache!
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2nd pic shows the results on my other 486.
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There's a ton of jumpers on this board, most of which I have no info on. Not sure if there would be one not set correctly that could causes this. I'm thinking it's related to whatever was keeping it from posting earlier.

Reply 14 of 24, by brostenen

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Shure it is not a cache-chip mismatch, wich are going on with the board? It looks like the chips you have used for upgrading the cache have more pins.

Don't eat stuff off a 15 year old never cleaned cpu cooler.
Those cakes make you sick....

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Reply 15 of 24, by probnot

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brostenen wrote:

Shure it is not a cache-chip mismatch, wich are going on with the board? It looks like the chips you have used for upgrading the cache have more pins.

That was my next thought. I disabled them (back to 128KB), same result - though my video card is now showing as 512k instead of 1024k??? Also its speed went way down.
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The chips are the same size, it's just the sockets that are smaller for the second set. I'm going to try pulling them entirely, but this is really weird.

EDIT: Just booted with the extra cache chips removed. Same AMD DX266 CPU I tried swapping in, same jumper settings (128k cache), and now the video card is back to 1024k and the same access speed as the original result.. but still slow CPU results and no L1 cache performance. I think this board has at least 1 (if not way more) broken traces...possible at the CPU socket or VLB slots (that's where I was wiggling it earlier to get it to post).

Reply 17 of 24, by probnot

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CkRtech wrote:

Is the turbo jumper closed?

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...I bumped the Turbo sw connector off when I was swapped video cards.

Yup....feelin' dumb. Should have realized when I was commented about the L1 cache -_-

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Reply 18 of 24, by 0101000000110101

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I'm so jealous!

The only AT computers I can find are...

$190-$600..

Except my entire Gateway 2000 P5-120 setup that I should showcase! That, I FOUND.

1995 Gateway 2000 P5-120
Intel Pentium P5 120Mhz
16MB EDO RAM
1MB Trident 3D capable GPU
250GB Western Digital IDE drive
OS(s): Windows 98/Windows 2000 SP1

Reply 19 of 24, by kixs

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CkRtech wrote:

Is the turbo jumper closed?

The 1st thing that crossed my mind 😉

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