Re: Help (re)building a 486

Posted on 2021-07-24, 02:22

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by jakethompson1

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Stick with FPM for 486s. EDO modules in 30-pin SIMM format do not exist, far as I know. I always shoot for the fastest possible speed DRAM, I say strive for 60ns. Even if your system doesn't explicitly require it, it's nice to have a little extra wiggle room for timing. Though, I think that if …

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Re: Fixing up an broken 486 I got from a local radio.

Posted on 2021-07-24, 02:05

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by jakethompson1

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

After Letting the board dry for a while to make sure there was no liquid left over, I plopped in the dx4, set the voltage to 3.3, crossed my fingers and booted the machine. It have me a happy post beep and popped up saying that it's cpu is a dx2 100, which I thought was curious. Maybe it's a bios …

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Re: How do DOS Option ROMS, boot process, XT-IDE work?

Posted on 2021-07-23, 21:22

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by jakethompson1

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

As I was thinking earlier, would it not also be possible to write a "stub" EMS driver for the card that makes a 64K page frame available but refuses all other EMS functionality (since the card has no ability to, in hardware, remap memory addresses) Even if a EMS 3.2 compliant EMS driver only …

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Re: How do DOS Option ROMS, boot process, XT-IDE work?

Posted on 2021-07-23, 21:19

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by jakethompson1

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Now you all have me thinking. What if, either using an EMS card, or a "hardwired" card like the Lo-tech linked in this thread, you were to load one of the valid option ROM addresses with something that either is or looks like a valid option ROM and then rebooted? Would the BIOS be tricked into …

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Re: How do DOS Option ROMS, boot process, XT-IDE work?

Posted on 2021-07-23, 21:11

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by jakethompson1

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

The BIOS will not put normal (read-write) RAM there. EMM386 takes care of creating UMBs by using features of the 386 processor to map virtual accesses to that 384KB region to either the same physical addresses (if there is video RAM/option ROM there), or to a different physical location in extended …

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Re: How do DOS Option ROMS, boot process, XT-IDE work?

Posted on 2021-07-23, 21:02

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by jakethompson1

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Thanks for the great answer! I think I got a much better picture of this now! The BIOS will not put normal (read-write) RAM there. EMM386 takes care of creating UMBs by using features of the 386 processor to map virtual accesses to that 384KB region to either the same physical addresses (if there …

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Re: How do DOS Option ROMS, boot process, XT-IDE work?

Posted on 2021-07-23, 20:27

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by jakethompson1

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Hello, I am trying to wrap my head around the mechanism that Boot ROMs work, in particular around booting and BIOS. After watching videos on the topic and reading XT-IDE and other BIOS ROM product pages, there are still some things I'm a bit uncertain about. Actually, quite a few things. 1) If I …

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Re: V4P895P3 / SMT V: 1.0 No boot with DX4-100 jumper settings

Posted on 2021-07-22, 03:19

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by jakethompson1

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Charleston wrote on 2021-07-21, 18:27: Gonna bump since I posted this late last night and it hasn't gotten any views. maybe take picture of your setup so everyone can see the video card, ram, jumpers, etc?

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Re: VLB Motherboard & Video Card Indentifcation Assistance

Posted on 2021-07-22, 03:02

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by jakethompson1

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I know this is an old thread, but this will hopefully help someone out. The 4DMU-HL3S is also known as the 4MHL3S. Jumper settings are available here: https://stason.org/TULARC/pc/motherboards/E/EFA-CORPORATION-486-4MHL3S.html http://www.win3x.org/uh19/public/motherboard/manual/31754.pdf Mine came …

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Re: Windows 3.0 Real Mode Software

Posted on 2021-07-21, 04:02

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by jakethompson1

in Marvin \ Software

in Marvin \ Software

Back when most ppl had 640K and Windows was just edging into people's consciousness, it was kinda regarded as a klunky DOS task switcher, and a desirable feature of DOS apps those days was to be "windows aware" not sure if that defines much really, I guess that it was well behaved, maybe could use …

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Re: Windows 3.0 Real Mode Software

Posted on 2021-07-21, 03:19

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by jakethompson1

in Marvin \ Software

in Marvin \ Software

yes i need real mode as i only have 640k ram i will get a 2mb ram board soon but apparently that still wont be enough to run in standard mode? 640K conventional+384K extended is enough for standard mode, e.g. on a PS/2 30-286. So the RAM board will need to give extended (not expanded) memory. Might …

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Re: Socket 3 486 Award Bios Modding

Posted on 2021-07-21, 00:50

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by jakethompson1

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Thanks, I’ll check this out. Can you elaborate on what you think might be happening between these two different bios files? Assuming you already know about MODBIN? And it's a deeper issue than enabling Assign IRQ for VGA under PCI/green setup (disabled by default in the UUD bios)? I’ve heard …

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Re: Socket 3 486 Award Bios Modding

Posted on 2021-07-21, 00:21

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by jakethompson1

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Chadti99 wrote on 2021-07-21, 00:00: Thanks, I’ll check this out. Can you elaborate on what you think might be happening between these two different bios files? Assuming you already know about MODBIN? And it's a deeper issue than enabling Assign IRQ for VGA under PCI/green setup (disabled by …

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Re: PC Chips M912 BIOS update for Am5x86 and Cyrix 5x86

Posted on 2021-07-20, 21:41

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by jakethompson1

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

What is the difference between 12/02/1995X and 12/01/1995 BIOS files? Is AMI better than Award? I recommend the AMI BIOS. In particular, it seems to handle IDE drives up to 8.4GB fine. The Award files floating on the first page of this thread, if you see there is a note that they may not actually …

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Re: Need to identify 486 motherboard and VGA/EGA graphic card

Posted on 2021-07-20, 21:26

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by jakethompson1

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

then try different dip switch settings (there's only 64 combinations XD ) Nooo lol 😑 I don't have any CRT monitor. If you google L4A0447 you might find pictures of a working card, like this one: https://www.worthpoint.com/worthopedia/286-clone-computer-3832702488 So maybe you can copy the jumper …

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Re: Need to identify 486 motherboard and VGA/EGA graphic card

Posted on 2021-07-20, 19:35

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by jakethompson1

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Are those boards the cache chips are mounted on a common thing? would that allow using cache chips that are no longer manufactured in DIP-32 format?

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Re: Buying/using NOS IDE hard drives

Posted on 2021-07-20, 03:01

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by jakethompson1

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Thanks for everyone's replies. Good info. I'll be picking up a few as I come across good deals. I'm aware that Seatools can reduce the space visible to the host on larger hard drives (i.e. reduce a 160 GB hard drive down to 30 GB), does it also work for other manufacture drives? Or perhaps WD tools …

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Re: Boosting scores on 386 benchmarks

Posted on 2021-07-19, 19:54

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by jakethompson1

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Is it the chipset? This mainboard is a bit undocumented and doesn't seem very good. Don't remember what chipset it has exactly but I believe it's some sort of OPTI. If I were to attempt to OC the 40mhz cpu to 50mhz with a 100mhz oscillator would that even work? I've heard of people doing it but I'm …

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Re: Video playback on retro PCs

Posted on 2021-07-19, 19:13

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by jakethompson1

in Marvin \ Software

in Marvin \ Software

Should also mention cutting back your frame rate. Video for Windows came with an example video still remember saying it operated at "15 frames per second, half the rate of television." And as mentioned, cut the resolution back drastically, maybe even to 320x240.

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Re: Video playback on retro PCs

Posted on 2021-07-19, 19:09

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by jakethompson1

in Marvin \ Software

in Marvin \ Software

My goal is to convert DVD files to a file format, downgrading its quality (but keeping the maximum quality possible), making it playable on my system. For this I need to know what program should I use, and what resolution/encoding settings/file format (compatible with subtitles), that would be the …

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