Re: 486 board with UMC 8881E/8886B: The winner is: EDO without L2 (terms and conditions apply)

Posted on Today, 10:56

by

by feipoa

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I've been casually working on an Am5x86-180 system for several months now. It has been a major headache. The path between my 180 MHz adventure and this thread have crossed so I thought I'd share some relevant findings. I first wanted to compare FPM vs. EDO on the Biostar MB-8433UUD board at 180 MHz …

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Re: So you want a Cyrix 5x86-133?

Posted on 2023-06-04, 18:11

by

by feipoa

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Why not use Wintune98? You could pull the results from just about every x86 CPU from the data table in the PDF of the Ultimate 686 benchmark comparison.

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Re: So you want a Cyrix 5x86-133?

Posted on 2023-06-04, 11:36

by

by feipoa

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

What’s the objective?

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Re: Custom interposer module for TI486SXL2-66 PGA168 to PGA132 - HELP!

Posted on 2023-06-01, 04:20

by

by feipoa

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

If either of you plan on desoldering the Am386DX, could you measure the 5V rail at the PGA CPU before and after removal of the Am386DX? I'm wondering how much voltage drop, if any, exists while having the Am386DX remaining installed and inactive. If you have a scope, it would also be interesting to …

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Re: Custom interposer module for TI486SXL2-66 PGA168 to PGA132 - HELP!

Posted on 2023-05-28, 23:17

by

by feipoa

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I see Cout connected. I don't see Cin. If I recall correctly from one of the datasheets, Cin was strongly encouraged. For MIC regulator, I'm using 121-ohm For LP regulator, I'm using 1K. The most likely cause of your non-responsive motherboard with the SXL installed is because you didn't disable the …

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Re: Information wanted for UMC UM8881F sub-revisions

Posted on 2023-05-24, 22:46

by

by feipoa

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I didn't have to do any modification of the board to use the BTS 8881F based chip in place of the EYA chip, but you are left with the limitations noted above. I have not swapped southbridge chips between AF and BF. I suspect the BF has the PS/2 mouse support built-in, while the AF does not. Since …

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Re: 3 (+3 more) retro battle stations

Posted on 2023-05-23, 19:54

by

by feipoa

in Marvin \ System Specs

in Marvin \ System Specs

Adaptec AHA-1522B with SCSI2SD v6.

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Re: 3 (+3 more) retro battle stations

Posted on 2023-05-23, 10:55

by

by feipoa

in Marvin \ System Specs

in Marvin \ System Specs

Looking at your chart, I see that you were able to achieve up to 23.8 fps in DOOM using the BL3 at 2x50 and GD-5434 with Chaintech 340SCD. Using the same hardware, I have in my notes that I got my board up to 24.0 fps (3112 realtics) at 12.5 MHz ISA. Did you also notice that increasing the ISA clock …

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Re: Market value for popular or rare classic computer hardware

Posted on 2023-05-22, 18:20

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by feipoa

in Milliways

in Milliways

Here's two items I was watching. They are rather obscure upgrades for less popular platforms - 386SX and 486SX (QFP). Make-It 486 upgrade for the 386SX . The upgrade uses a TI486SXLC2 at 50 MHz. Sold for $365 + $44 shipping from S. Korea. $409 USD https://www.ebay.com/itm/334866454556 Make-It-486_ …

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Re: Market value for popular or rare classic computer hardware

Posted on 2023-05-14, 07:11

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by feipoa

in Milliways

in Milliways

A few items I was watching. IODATA PK-X486 with PLCC connector. Turns your 286 into a TX486SLC with clock doubling. $313. Boxed unit. https://www.ebay.com/itm/334845788215 PK-X486_286_to_Ti86SLC.png IODATA PK-X486S50-3 with PLCC connector. Turns your 286 into a 16-bit IBM Blue Lightning 486 with …

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Re: Original Voodoo 5 6000 prototype for sale on eBay

Posted on 2023-05-10, 10:12

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by feipoa

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

If the Voodoo3 2000 was $120 and the Voodoo3 3000 was $150, what was the equivalent cost for the Banshee?

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Re: ISA DMA issues in DOS with SiS 496/497 based motherboards

Posted on 2023-05-09, 10:15

by

by feipoa

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I tried to replicate pshipkov's workaround methods for getting DOS sound working by a) setting L1 to WT, and b) disabling L1 entirely. I tried using an AWE64Value and an OPL3 card with the 1/2*FSB divisor enabled for PCI, but still DOS sound will not work, whether or not I set L1 to WT, or disable …

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Re: ISA DMA issues in DOS with SiS 496/497 based motherboards

Posted on 2023-05-09, 08:53

by

by feipoa

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I can confirm that removing the jumper from JP8, pins 6-7 sets the Am5x86 into L1:WT mode. Thanks a lot; saved me some probing work! Now let me see if I can replicate pshipkov's symptoms.

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Re: ISA DMA issues in DOS with SiS 496/497 based motherboards

Posted on 2023-05-09, 07:11

by

by feipoa

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I don't feel proud of my contribution to this thread, so thanks for putting up with it. We have to topics mixed-up. 1. My problem that i started the thread with AWE64 Gold having problems in DOS when L1 cache is in WB mode. 2. Your problem, where Yamaha OPL3 based card is having problems at 3x60MHz …

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Re: ISA DMA issues in DOS with SiS 496/497 based motherboards

Posted on 2023-05-09, 00:11

by

by feipoa

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I did not see your edit. The continual edits in this thread have made it hard for me to follow. JP8, pin 6 does not go to WB/WT#. There is a 4.7 K-ohm resistance path between JP8, pin 6 and WB/WT#. Before I posted my comment concerning JP13, pin 3 being WB/WT#, I had already checked all the CPU …

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Re: ISA DMA issues in DOS with SiS 496/497 based motherboards

Posted on 2023-05-08, 12:49

by

by feipoa

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

If I made a mistake, I don't know where. I'm attaching my measurement photos. Maybe you'll spot something I missed. Filename Am5x86_pins_printed_and_flipped_over.JPG File size 373.97 KiB Views 85 views Filename LSD_WB-WT_pin_multimeter.JPG File size 1.91 MiB Views 85 views

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Re: ISA DMA issues in DOS with SiS 496/497 based motherboards

Posted on 2023-05-08, 09:39

by

by feipoa

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

My DMA sound problems only arise when using the PCE = 1/2*FSB jumper. How are you setting the LSD for L1:WT mode? I've attached the manual for this board. Are you using the jumper settings for either: (D) INTEL -SLE 486 DX/DX2/DX4 & 486 OVERDRIVE or (E) AMD DX/DX2/DX4 (NV8T) ? I trace the WB/WT# pin …

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Re: ISA DMA issues in DOS with SiS 496/497 based motherboards

Posted on 2023-05-08, 06:59

by

by feipoa

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Ok, i confirm that with L1 in WB the DMA issue is not present. I'm so confused right now. I think you meant to write WT instead of WB. Could you try using a Yamaha OPL3 type of sound card w/WB mode enabled? I don't have any issue with L1:WB Am5x86 with DOS sound using OPL3SAx, provided PCI=FSB. …

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Re: Original Voodoo 5 6000 prototype for sale on eBay

Posted on 2023-05-08, 02:39

by

by feipoa

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

At the very end near $15,000 there's a "zero" feedback bidder, whom is no longer registered. And then there's a low feedback bidder with 24 retractions in the past 12 months involved since the mid $10,000's up until the mid $14,000's. These could be contributing factors as to why the sale fell …

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Re: Original Voodoo 5 6000 prototype for sale on eBay

Posted on 2023-05-07, 21:12

by

by feipoa

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Shponglefan wrote on 2023-05-07, 17:05: Linus Tech Tips was apparently loaned this exact card and just released a video about it: https://www.youtube.com/watch?v=IrWfhbqURC4 The deal fell through? If the card wasn't sold, I guess we don't know current market value.

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