Re: Issue with 386sx (Acermate 333s) - IDE HDD

Posted on Yesterday, 14:18

by

by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Probably not. Unless there is a jumper on the mobo to disable the built-in IDE, which I doubt. Also that card you mentioned (Lo-tech XT-CF-lite rev.2) is 8-bit only and most likely uses XT, not AT, port for the IDE channel. So it will be slow at best, might not work properly at all in AT system. …

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Re: Issue with 386sx (Acermate 333s) - IDE HDD

Posted on 2024-06-07, 21:29

by

by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

The mother board has only 1 IDE hdd . Ah, so it's a mobo with built-in IDE controller. In that case it's quite possible there is a problem with signal connection to that IDE connector. The glitching bits are 11, 12 and 14, That would be pins 10, 12 and 16 on the connector. First check if the pins …

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Re: Issue with 386sx (Acermate 333s) - IDE HDD

Posted on 2024-06-07, 13:31

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by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Is this the sign of failing board ? The geometry should be 992/8/32, and that's 0x03E0/0x0008/0x0020 in hexadecimal. What you have there on the screen is 23520/22536/22560, which is 0x5BE0/0x5808/0x5820. Notice anything interesting? If we subtract 0x5800 from each value we get correct results. In …

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Re: 5" Floppy NEC FD1053 - help for jumper settings ?

Posted on 2024-06-07, 08:49

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by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

But when I use a double cable (one part with a twist in the cable), then it doesn't work, also shows a floppy failed error 40 at boot. I already tried with 2 cables. Did you connect the cable properly? One sure sign you didn't is the floppy LED is on all the time, from the moment you power the …

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Re: Looking for volunteers with XT / 286 systems with a co-processor

Posted on 2024-06-05, 13:11

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by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Intel manuals are better than nothing but it seems there's plenty of various errors or omissions in them. Possibly Intel was working more closely with various software companies and let them have updated docs which were never made public. Some CPU errata information appears to have been distributed …

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Re: Advice for good soldering workshops in the Netherlands, preferably in the Amsterdam area?

Posted on 2024-06-04, 22:29

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by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Can any of you maybe recommend any good workshops for people who wish to gain more experience with soldering, tailored towards hobby electronics, including retro computer hardware tinkering? Consider YT videos. Some are great, some not so much, but it's free and you can pick a teacher and lesson …

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Re: Intel Pentium prototype?

Posted on 2024-06-04, 21:59

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by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

That thing shouts fake to me. Or perhaps it is some sort of memento, made way later out of dead chips. I haven't worked at Intel, or designed any chips, but I've seen prototypes. You do not put a logo and other brand markings on a prototype. Laser engraved serial on the package - maybe. But no …

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Re: Fixing CT-6BTM0 motherboard - C0, C1 and then ambulance alarm

Posted on 2024-06-03, 18:59

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by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

The cheapest ATX extension cables from china are using below-standard wire widths! 18AWG should be standard so make sure your extension cable is at least that. That reminds me that I bought a pack of breadboard connection wires and for some reason my contraption didn't work properly. Turns out the …

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Re: Pc power and cooling power supplies

Posted on 2024-06-02, 23:52

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by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

starter capacitor, those commonly go out on things like HVAC units after about 5-10 years Apples. Oranges. Oil AC capacitors die because of the working conditions - direct connection to noisy line with all the voltage spikes. Then there is heating, both external and internal - there will always be …

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Re: Cyrix 5x86 on older 5V-only 486 motherboards

Posted on 2024-06-02, 15:37

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by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

It's pretty amazing (...) You seem to have misspelled "cheap" :) I always wondered how many of these mobos were using licenced, actually paid for, BIOSes. IIRC there were some no-name mobos that just stole the BIOS off some other product (it was a clone so little to no work needed, other than some …

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Re: Pc power and cooling power supplies

Posted on 2024-06-02, 11:34

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by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I never had any issues with PC PSUs until AMD Athlon/Duron era. At this point the local market was flooded with cheap, nasty Chinese inventions that had ever higher W/A numbers but the insides were more and more "optimized" for mass production. I actually had 2 or 3 go bang on me in the summer, and …

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Re: Fast Ethernet on ISA

Posted on 2024-06-01, 18:44

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by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I've run some Linux benchmarks. Results from my K6-2 system convinced me to try some synthetics as well. Conclusions so far, in no particular order: * I tested only early Debians (Buzz and Potato), with kernels 2.0.36 and 2.2.26 - it's very unlikely I'd be using ISA network cards with anything newer …

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Re: Do you always open and clean newly acquired CRT? My experience...

Posted on 2024-06-01, 17:54

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by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I like my CRTs clean. Especially the pre-owned ones, since I have no idea who used them and for how long, I don't want all that stuff wented out with hot air into my lungs. It also simplifies repairs, clean PCB is much easier to work on, not to mention being able to spot obvious issues right away.

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Re: Seagate ST-157A

Posted on 2024-05-30, 09:10

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by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

No, I meant replacing the burned out element in red circle with a wire, since it was most likely a choke and you won't be able to guess now what particular value it had (probably a few uH). Well I suppose you could try to use thinner wire that would be like a fuse but that is a lottery. Too thick …

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Re: Cyrix 486DLC-40 with Cyrix Fasmath 83D87-40-GP Benchmarks

Posted on 2024-05-28, 15:10

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by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Not 100% sure what "Cyrix optimization sw" is, I assume the internal cache control program? You are still being held back a bit by lack of Write-Back mode in mobo cache. In Lanmark 6.0 I get 168 MHz AT, 164 MHz 80287, 5146.81 chr/ms. 65.7 in Norton SI 8.0, 6.2 in PC Player Benchmark 320x200 mode. …

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Re: Dead p2-450?

Posted on 2024-05-28, 14:39

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by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I did manage to get it to show some post codes (can't recall what) but haven't been able to reproduce it. On this mobo or known good one? Because it could be a slot issue, these are not very robust - I have heard stories about bad slots. Usually issues developed by twisting the CPU too much, …

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Re: Dead p2-450?

Posted on 2024-05-28, 13:08

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by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

That's a flip-chip design IIRC, such a tiny piece missing on what is the back of the substrate shouldn't really kill the CPU. Clean the gold pads with IPA, make sure you have good contact in the slot.

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Re: Seagate ST-157A

Posted on 2024-05-28, 13:03

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by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I think the capacitor is shorted and caused the SMD in front of it to burst Most likely a choke then but do make sure, if putting a piece of wire across the pads doesn't short the power connector then it's pretty safe to test the HDD with this "fix". After you replace the cap the blew up of course, …

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Re: Fast Ethernet on ISA

Posted on 2024-05-28, 10:09

by

by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Still, be careful - the slowdown resulting from duplex mismatch may be moderate on a quiet network, but much heavier when the network gets busy. I'll think about how I could simulate such a thing. Unless I use coax there will always be somewhat modern store-and-forward network switch isolating that …

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Re: Fast Ethernet on ISA

Posted on 2024-05-28, 09:00

by

by Deunan

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

A synthetic test would probably give me more clear-cut results (I will try something like this with Linux test) but then again if I see no difference in a test that is my typical use case then why would I worry about the FD setting? It's not like I'm trying to squeeze the last bit of the performance …

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