Re: 100Mbps PCI NIC that does *not* bus master

Posted on 2021-07-15, 23:31

by

by jakethompson1

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

maxtherabbit wrote on 2021-07-15, 20:26: Didn't seem to work, which is unsurprising since all the parameters in that key were laid out into subkeys and not just plain string values Is it the 3c59x or the 3c90x driver that you are using? Remember these are NDIS, so the same drivers are (usually) …

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Re: IBM PS/1 processor upgrade.

Posted on 2021-07-15, 01:04

by

by jakethompson1

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

The Intel DX4ODP75 comes with a built in voltage regulator and heatsink. If you're replacing the existing CPU, make sure you get the DX4ODP R version. The DX4ODP is meant for an overdrive socket. Are you sure? I see that someone posted a picture of the motherboard now, and I thought so too at first …

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Re: IBM PS/1 processor upgrade.

Posted on 2021-07-14, 23:13

by

by jakethompson1

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

A DX4-75 would be the easiest and most compatible upgrade, I think. The Intel DX4ODP75 comes with a built in voltage regulator and heatsink. You'd have to weigh that against buying the three parts separately. You could get a DX4-100 upgrade and just run it underclocked too. As you mention, the …

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Re: IBM PS/1 processor upgrade.

Posted on 2021-07-14, 22:56

by

by jakethompson1

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

First question would be whether the board has multiple clock rates or is stuck at 25 MHz.

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Re: 286 with 1MB RAM - any way to get 640K Conventional?

Posted on 2021-07-14, 21:16

by

by jakethompson1

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Early 286 mainboards in fact did not support the 640+348 configuration, because that one is technically more difficult to handle than 512+512. So rmay634703 is correct that the only way to make use of all mainboard RAM and get 640K conventional is using a 16bit ISA memory expansion card. On 6MHz …

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Re: 3 (+3 more) retro battle stations

Posted on 2021-07-14, 06:05

by

by jakethompson1

in Marvin \ System Specs

in Marvin \ System Specs

So you put device=c:\um8673.sys into the config.sys, but what file do you edit to set the speed, e.g. Speed 16, 17, etc ? I assume those speeds are MByte/s values? Note that I have the MB-8433UU C -A which has the UM8886 A F rather than BF, but they seem similar. One difference is with this board, …

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Re: So embarrassing..what's the default bios password for this PC Chips Cheetah 486 board v1.7 motherboard?

Posted on 2021-07-12, 05:14

by

by jakethompson1

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I am encountering this problem now with a PCCHIPS M918. I have absolutely no chance. CMOS resets, leaving it without a battery, etc. does not help. Entering the BIOS is not possible. All the passwords, that I tried, don't work. Even if I use a BIOS from another Board with the same chipset, it asks …

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Re: CacheCHK and Socket 3 Pentium Overdrive POD83

Posted on 2021-07-12, 03:42

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by jakethompson1

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Looks like 16K for code and 16K for data so your results make sense

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Re: AMI Color BIOS (1993 and earlier) modification in hex editor

Posted on 2021-07-12, 01:25

by

by jakethompson1

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Nice to see this information retained online now. It is probably too involved for most users of the forum, but that could change in time. Now you know what it's like for us reading your directions on upgrading the 8433UUD to 1024k cache, modifying the keyboard controller to add a mouse port, etc. " …

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Re: 486 - Brief sign of life upon power up

Posted on 2021-07-10, 05:51

by

by jakethompson1

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I tried powering it up again tonight with different RAM this time to the exact same result: The fan spins about one rotation upon power-on, then nothing, and then about one rotation upon power-off. I did notice a quiet electrical noise rising in frequency just before the fan spun, a build up of …

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Re: PCI slots fouling CPU heatsink

Posted on 2021-07-09, 19:47

by

by jakethompson1

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

The HOT-591P also had this issue. My understanding was the official recommendation was a low-profile copper heatsink.

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Re: Where can I find "AMIBCP" (for DOS) ?

Posted on 2021-07-09, 02:10

by

by jakethompson1

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

No that is not the original AMIBCP for Windows 1.0, was hoping to find it..... Again though, is there something specific you are trying to do with a 10/10/94 bios? Like the other thread I posted for non-WinBIOSes, it may be easier to analyze the bios and figure out how to do what you want, although …

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AMI Color BIOS (1993 and earlier) modification in hex editor

Posted on 2021-07-08, 01:40

by

by jakethompson1

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I saw the AMIBCP search thread was active again. In talking with some of the members about the PS/2 mouse hardware modifications on their boards, there are at least a few modifications you can do with these BIOSes even without having AMIBCP, found by digging around in the hex dump, DOS DEBUG, and in …

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Re: Where can I find "AMIBCP" (for DOS) ?

Posted on 2021-07-06, 16:36

by

by jakethompson1

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

The oldest Windows version I have is 2.42. The oldest DOS version I have is 5.11E. It would be nice to get a hold of every version between 1.0 and 5.0, but I'm feeling pretty pessimistic about this. The odds are about as good as finding a MR BIOS image for the VLSI topcat. I would like a copy of …

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Re: Is there a dosbox version for 486?

Posted on 2021-07-06, 15:23

by

by jakethompson1

in PC Emulation

in PC Emulation

It's an interesting idea but yeah I don't think full emulation would be the way to go. I wonder if you wanted to implement the features you mentioned, if you most likely would end up creating something along the lines of SoftICE.

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Re: Where can I buy? CMOS 4-PIN Battery Replacement

Posted on 2021-06-16, 22:28

by

by jakethompson1

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

maxtherabbit wrote on 2021-06-16, 22:09: It's a standard 0.100" pitch pin header. You can get them at digikey or ebay or anywhere Digi-Key also stocks the whole thing as BH3AA-211. Pricier, but maybe not if you factor in shipping on two orders.

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Re: IDE support for more than 8 GB HDD storage on Biostar MB-8433UUD

Posted on 2021-06-15, 23:55

by

by jakethompson1

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

On Wikipedia it looks like PIO mode 3 was only rated for 11 MB/s anyway, so there was no way it would match the UltraDMA card. Programmed I/O ties up the CPU running a REP INSD instruction to read from the bus only 32 bits at a time. I don't know whether the fault for the slow times (vs. what PIO3/ …

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Re: Can't get into CMOS setup on old 486.

Posted on 2021-06-13, 16:11

by

by jakethompson1

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

In effect I suppose the improperly configured cache made the first 64K work incorrectly. This was also mentioned earlier the discussion - BIOS was never able to proceed far enough. Interesting. I'm surprised it wouldn't give you the opportunity to enter CMOS setup before enabling the external cache …

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Re: Can't get into CMOS setup on old 486.

Posted on 2021-06-11, 15:11

by

by jakethompson1

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

You've mentioned that the board has a 50 MHz crystal. I thought that for 386 CPUs, the crystal is double the clock speed, and for 486 CPUs, the crystal is equal to the clock speed, but with this being a DX2 CPU, it would actually be half the clock speed. So I think the crystal should be 25 MHz. …

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Re: Can't get into CMOS setup on old 486.

Posted on 2021-06-11, 01:25

by

by jakethompson1

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I think one of those old BIOS chips have a failed/corrupted section in one of them. Have a P2B bios chip that has a bad spot and would lock during POST, found it with a TL866 when trying to read the contents to make sure it was same as what was supposed to be programmed in it when it failed a flash …

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