Re: Adding a secondary floppy controller w/ BIOS

Posted on 2022-10-06, 20:35

by

by eesz34

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

In my experience, floppy card option ROMs tend to be speed sensitive and don't like being shadowed. How fast is the system and can you disable shadowing for the ROM? Sergey's floppy ROM in particular also has other issues, it is very slow for example It's 133MHz and all the shadowing is disabled. …

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Re: Adding a secondary floppy controller w/ BIOS

Posted on 2022-10-06, 20:10

by

by eesz34

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

well at least I made my driver only take up a little bit of memory :D Hey it's you! Yes, about 6K so not that bad. But from a purist's point of view he'd want no driver required for something that the integrated controller seems to get by without. That is, that DOS picks up those drives …

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Adding a secondary floppy controller w/ BIOS

Posted on 2022-10-06, 19:44

by

by eesz34

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I posted about this a few months ago, but have a different set of questions about this now. I have a P5 MB with an integrated controller that supports 2 drives, but want to add a 3rd floppy drive. So I built Sergey's Monster Floppy controller and populated only the secondary controller, which is on …

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Crowbar on power supply

Posted on 2022-09-27, 14:12

by

by eesz34

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Has there been discussion about adding crowbar protection to old power supplies? I know hardware damage caused by the power supply might be rare, but I think it would be cool to have a crowbar board that would plug into the 4 pin drive connector. Fairly simple to design, too.

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Re: Bought these (retro) hardware today

Posted on 2022-08-30, 14:48

by

by eesz34

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Just won something a bit different for me (seller's photo) s-l1600 (2).jpg A complete Apple Macintosh LC that is dead... be a fun little project! Buying computers that are dead is a great way to get a deal. Many won't touch it, and good chance it's not a major repair. I bought an old Prolinea that …

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Re: Max colors from WD90C31

Posted on 2022-08-15, 12:31

by

by eesz34

in Marvin \ Video

in Marvin \ Video

I have a Prolinea 3/25 that has a WD90C31 video chip and am wondering if it can display more than 256 colors at lower resolutions. Since it has 512KB RAM, I know anything beyond 256 colors at 640x480 is an impossibility. But I'm trying to determine if maybe 320x200 can do more colors on the screen. …

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Re: Anyone have AT form factor specification?

Posted on 2022-08-02, 13:52

by

by eesz34

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Thank you so much. Good to know it isn't because mine is screwy. And yes, I did notice something with the video card when I took these pictures but couldn't immediately determine what it was. It went in easy as did the other two boards in there. And looking at the uncropped picture, the NIC two …

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Re: Sunbrighting a disgustingly yellowed keyboard: A Visual Experiment

Posted on 2022-07-29, 11:52

by

by eesz34

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Not entirely there yet, but the case has whitened perfectly and the keycaps are a way healthier beige than the previous sickly yellow they were. Hopefully sitting in the sun through August will return the whole keyboard to its initial color and I can hook it up to my XPS D333 :sunglasses: Wow! …

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Re: Anyone have AT form factor specification?

Posted on 2022-07-29, 11:48

by

by eesz34

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Could you measure something on it so I can compare? A good one might be distance from the closest edge of the closest slot to the closest point on the keyboard hole. See picture for description and my measurement. For what it's worth I used a caliper around those edges, but the keyboard port …

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Re: Anyone have AT form factor specification?

Posted on 2022-07-28, 15:49

by

by eesz34

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Yes, the specifications appear to have been fairly loose. I've had great difficulty getting certain AT motherboards into supposed AT cases. Also, certain ISA cards won't fit in certain AT cases/boards - you have to remove the I/O bracket to use them, because the alignments are all wrong. I had this …

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Re: Anyone have AT form factor specification?

Posted on 2022-07-28, 15:46

by

by eesz34

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I have that case and it lines up with the motherboard I have in it. https://www.vogons.org/viewtopic.php?f=25&t=84289 Could you measure something on it so I can compare? A good one might be distance from the closest edge of the closest slot to the closest point on the keyboard hole. See picture for …

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Re: Anyone have AT form factor specification?

Posted on 2022-07-26, 23:02

by

by eesz34

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Just found an interesting picture, probably not interesting to many of you experts out there. But this pic shows a keyboard hole in a no-name type case that's oblong, so apparently there were issues with this. https://ancientelectronics.files.wordpress.com/2014/04/386alt2.jpg Come to think of it, I …

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Re: Anyone have AT form factor specification?

Posted on 2022-07-26, 22:54

by

by eesz34

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

It's harder than it might seem to do this measurement with any precision using a sliding caliper, so take this with a grain of salt. Got 31.8 mm from edge to the center of the connector. DSC_6938.JPG Measuring mobo edge - connector edge (42.5 mm), and subtracting half the connector's measured width …

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Re: Anyone have AT form factor specification?

Posted on 2022-07-26, 22:32

by

by eesz34

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I got this NOS AT case and motherboard, and the keyboard connector is not centered in the case hole. It's strange, I've never expected this would even be a thing. From the case's perspective, the keyboard connector is too close to the expansion slots. The keyboard plug does fit into it without …

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Re: Anyone have AT form factor specification?

Posted on 2022-07-26, 22:29

by

by eesz34

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Supposedly the IBM XT 286 (5162) motherboard was the first Baby AT form factor and where it's derived from. Right! I think the only difference is that some of the mounting hole positions are taken from the original AT boards (though in some cases boards have holes that match both XT and AT). I'll …

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Re: Anyone have AT form factor specification?

Posted on 2022-07-26, 21:44

by

by eesz34

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

On a random ASUS Socket 7 motherboard I have at hand I measured 23mm from the center of the mounting hole to the center of the keyboard connector. I made the measurement at the edge of the board. Can you post pictures of the case you're having the problem with? Unfortunately this kind of annoyances …

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Re: Anyone have AT form factor specification?

Posted on 2022-07-26, 20:58

by

by eesz34

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I got this NOS AT case and motherboard, and the keyboard connector is not centered in the case hole. It's strange, I've never expected this would even be a thing. From the case's perspective, the keyboard connector is too close to the expansion slots. The keyboard plug does fit into it without …

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Anyone have AT form factor specification?

Posted on 2022-07-26, 15:44

by

by eesz34

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I got this NOS AT case and motherboard, and the keyboard connector is not centered in the case hole. It's strange, I've never expected this would even be a thing. From the case's perspective, the keyboard connector is too close to the expansion slots. The keyboard plug does fit into it without …

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Re: Bought these (retro) hardware today

Posted on 2022-07-24, 00:54

by

by eesz34

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Not very retro, but old enough to get a good deal: a full FX 6100 system minus any hard drives for $25.00. The seller even had the spare cables for the power supply, and the power supply alone was worth the price. Sixteen gigabytes of DDR3 1600, a USB 3 card, a Syba SATA card (he had lots of drives …

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Re: Why doesn't MPXPLAY work?

Posted on 2022-07-22, 19:05

by

by eesz34

in Marvin \ Sound

in Marvin \ Sound

I only have 8MB RAM in this right now, could that be it? It's possible. Honestly, I'm not sure what the system requirements for MPXPLAY are. Maybe it's listed in the program documentation. For reference, I have 64 MB RAM on the Pentium MMX rig which houses my OPTi card. Just got more RAM, and that …

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