Re: Evergreen revto486.sys parameters and manual

Posted on 2020-07-30, 10:27

by

by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Did you patch the IO.SYS of MS-DOS or Towns OS? If you did, could you share the information? According to the documents of CXSET, IO.sys should be patched. But how to do is difficult to find. I've made some changes to my own cache enabler and now the Psygnosis games seem to boot, at least some of …

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Re: Collecting rants

Posted on 2020-06-15, 19:44

by

by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Or just stop dealing with people like you who are too lazy and too slow to understand how business really works. That simple. Take your negative seller's rating and go on your merry way. Well then, I hope all your clients treat you in the way you just described. And with that said I think this is …

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Re: Help resurrecting a Gateway 386SX/25

Posted on 2020-06-15, 13:50

by

by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

OK thanks for clarifying! I went at the card with a multimeter, and only one of them beeped! So I am guessing that's our culprit? I still would rather change them all for future proofing. That's a good start at the very least. You can trace the copper back to the PSU connector and I'm pretty sure …

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Re: Collecting rants

Posted on 2020-06-15, 13:38

by

by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Expecting a message within 1-2 days is not "here and now". It's just normal especially from sellers who use gmail so they get a notification on their smartphone. The "I'm too busy to reply or go to the PO" line is usually a bullshit excuse for lazyness after the buyer already paid. It's the same as …

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Re: which 486 cpu pin is connected/talks to the cmos

Posted on 2020-06-13, 12:36

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by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Now I need to try track down the hardware route I can see there were some repairs done to this mobo after the battery spill corroded some traces? In my experience any issues with accessing the CMOS or ISA bus in general are due to broken connection in that area. So double, triple check every piece …

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Re: Collecting rants

Posted on 2020-06-12, 23:23

by

by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I hate when sellers take forever to reply to a message. People are literally fused with their smartphones but don't have time to answer a simple question? Please. (...) I also hate when it takes 4-5 days to ship a simple item I ordered. Frankly, if there is something that does annoy me, it's that …

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Re: BIOS for old 286

Posted on 2020-06-12, 13:21

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by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

babtras wrote on 2020-06-12, 02:24: Pics of the motherboard attached. A bit OT but man, one look at that mobo and I knew it's a JP system. All these weird connectors and track layout... I hope you get it running.

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Re: Help resurrecting a Gateway 386SX/25

Posted on 2020-06-10, 20:53

by

by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I meant to use the transistor tester to know which value they are. The multimeter will not tell me what value they are. How would I even know the polarity even? I don't want to base myself on any assumptions. That's usually not possible in-circuit but in this case, since the riser can be detached, …

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Re: Help resurrecting a Gateway 386SX/25

Posted on 2020-06-10, 18:50

by

by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

You mean the ones in the riser board or the motherboard? You lost me. Didn't you just state the mobo works but PSU acts like there's a short if you install the riser? If so, where do you think the shorted caps can be, the mobo or the riser? I'd say the riser is the logical conlusion. Also why would …

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Re: Help resurrecting a Gateway 386SX/25

Posted on 2020-06-10, 17:26

by

by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Now I don't understand what could be wrong here. Here's a pic of the riser board: As you see it's just a bunch of capacitors? and that's all. Yup. What I said, one or more of those are internally shorted. Most likely the -12V one as the +12V would likely just explode and catch fire, but possibly …

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Re: Cyrix/Texas Instruments 386 to 486 upgrade chip question

Posted on 2020-06-10, 09:04

by

by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Preferably you need 2 things: 1) BIOS support for 486, even if it's just for the SLC/DLC 2) All 3 signals KEN#, FLUSH# and A20M# connected Now, without BIOS support the mobo might not even boot. That'a a major problem. If it does boot but doesn't support/recognize the CPU it'll work but most likely …

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Re: Help resurrecting a Gateway 386SX/25

Posted on 2020-06-08, 19:53

by

by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

And then, the motherboard is acting as if it was shorted when connected to the ATX PSU, so I think maybe the PSU took it with it or something. Need to inspect more. Does it have tantalum capacitors? Those tend to fail short - it's a chemical reaction with water and oxygen from air if it cracks, and …

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Re: 386 mainboards without cache

Posted on 2020-06-08, 14:52

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by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I was wondering if the nail polish actually protect for conduction or short circuit. I understand it sure make a layer on them but what about conduction? I've yet to find one that would be conductive - but if you want to be sure, just paint a bit of wood, let it dry, than measure yourself. BTW …

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Re: 386 mainboards without cache

Posted on 2020-06-08, 13:13

by

by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Just out of curiosity (and maybe it's a stupid question), but is it actually necessary to cover up exposed PCB traces? Mostly to prevent corrosion (especially if you live anywhere near salt water bodies) and any accidental shorts. Nail polish (doesn't have to be clear one) is ususally fine, even …

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Re: TI 486SXL and 486SXL2 PGA168 on socket 3 motherboards

Posted on 2020-06-08, 12:57

by

by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Was the SXL really TI's attempt to avoid making a true 486? I think the SXL came out only slightly before the TI486DX2/4. The timing might have been affected by some other factors. Or, perhaps, it was a big enough batch of unsold SXL chips that Ti wanted to get rid of ASAP knowing the new DX line …

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Re: TI 486SXL and 486SXL2 PGA168 on socket 3 motherboards

Posted on 2020-06-07, 23:45

by

by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I'm going to assume the (much less common) TI 486SXL CPUs in PGA-132 form factor are mostly plug-in compatible in 386 or 486/486 boards without some of the quirks of these PGA-168 CPUs. Hmm, but come to think of it, if these SXL CPUs are fully electrically compatible with the 386 bus, they could …

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Re: 386 mainboards without cache

Posted on 2020-06-07, 23:23

by

by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

chrismeyer6 wrote on 2020-06-07, 18:43: I had a 386 board years ago that had a soldered dx-40 and a socket and if you inserted a cpu it automatically disabled the on board one. What mobo was that, do you remember? Because all the ones I've seen require a jumper to be moved to disable the on-board …

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Re: Olivetti pcs 286 power supply problem

Posted on 2020-06-06, 18:49

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by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I'm getting really frustated with this... I now that without a proper load, the power supply doesn't work well, and i expect some oscillations, but not of this magnitude.. Then why not try lightbulbs as I've suggested? These are easy to come by and cheap, and make a great load since it's purely …

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Re: Olivetti pcs 286 power supply problem

Posted on 2020-06-04, 22:13

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by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

it's lihe less than half a second.. jumping up down... I can see and ear the power supply fan accelarating and desacelarranting when the voltage is low or high Could be simply not enough load, or some dried out caps on the secondary side and/or the PWM controller supply. Attach a car 21W 12V bulb …

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Re: Is this i386 an engineering sample?

Posted on 2020-06-01, 17:59

by

by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

It must have been pretty embarrassing for intel to admit that their brand new (and very expensive) 32-bit CPU could only run 16-bit code. Although everybody likes to talk about FDIV, this was a far bigger F@#% up in my opinion. It wasn't the only significant bug in 386, although most other ones …

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