Re: Success: Adding a PS/2 mouse port to the Shuttle HOT433 (using a dedicated keyboard controller chip)

Posted on 2025-04-16, 12:57

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by feipoa

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Has anyone has tried this mod on the v4 boards yet? The layout for the strapping resistors looks identical to v1-3 boards.

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Re: Lets make new M919 Cache sticks?

Posted on 2025-04-16, 12:49

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by feipoa

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I think I’m going to try different memory chips. Will try these next https://au.mouser.com/ProductDetail/Renesas-Electronics/71V124SA10TYG8?qs=GVScuG1d83gM2mgZp%252Bu1Lg%3D%3D I’m also going to use a heat plate at 260c and solder paste to reduce the time it takes to solder every single leg of the …

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Re: Register settings for various CPUs

Posted on 2025-04-16, 10:28

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by feipoa

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

If I'm remembering things correctly, sometimes changing the Fast Gate A20 Enable/Disable option in the BIOS will also clear that himem error.

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Re: Register settings for various CPUs

Posted on 2025-04-16, 07:25

by

by feipoa

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

-x0,64 may be needed, as suggested by rasz_pl. I think he suggested it for some A20 failures. Remark from me: I also had himem.sys a20 control issue with the ti486. I could resolve it by adding "/machine:13" option. You got your SXLC2-G50 working completely now? How did you land upon /machine:13? …

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Re: PcChips M919 - voltage modification the easy way

Posted on 2025-04-11, 20:59

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by feipoa

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I was also noticing that TSOP's tend to perform the best when overclocking old 486 systems.

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Re: PcChips M919 - voltage modification the easy way

Posted on 2025-04-09, 01:12

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by feipoa

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

bertrammatrix, you should have your 64 MD modules now. Would you be willing to upload a photo of the module and identify which IC's are on the PCB? Thanks.

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Re: Success: Adding a PS/2 mouse port to the Shuttle HOT433 (using a dedicated keyboard controller chip)

Posted on 2025-04-05, 13:07

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by feipoa

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I finally got around to modding one of my HOT-433 v1-3 boards for PS/2 mouse support. Everything worked just fine. Thanks to mkarcher for taking the time to figuring this out. I bent out pin 2 per the suggestion. VIA KBC works fine. I also tested the original Shuttle HOT-433 WINBIOS version 433AUS26 …

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Re: PcChips M919 - voltage modification the easy way

Posted on 2025-04-03, 06:18

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by feipoa

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

After some back and forth, it appears that this sell does not have the 64 MB, single-sided, 3.3v VRM, EDO modules with K4E640412D-TC50. For Samsung, they only have: KM44V16104BS-6. I will be interested to hear what modules you actually receive.

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Re: Necessity of TCK, TDI, TDO, TMS pins on Am5x86 and Cx5x86 CPUs?

Posted on 2025-04-01, 03:11

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by feipoa

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I have a few bare interposers which are wired for Cx5x86 and Am5x86 already. I found the copper coloured interposer before I found the bare 5x86 interposers. Since the Cyrix 486DX2V80 on the copper interposer wasn't working, I thought I could re-purpose the interposer as there's no other use for it. …

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Re: Necessity of TCK, TDI, TDO, TMS pins on Am5x86 and Cx5x86 CPUs?

Posted on 2025-03-31, 20:44

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by feipoa

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

The adaptor originally had a Cyrix 486DX2V (low voltage), which according to the table in the above linked URL, should have required less bodges. While the interposer looks like it was intended for Cyrix 486DX/DX2 5V, maybe it was hoped to also work with the low voltage variant and someone soldered …

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Re: Necessity of TCK, TDI, TDO, TMS pins on Am5x86 and Cx5x86 CPUs?

Posted on 2025-03-31, 08:29

by

by feipoa

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Thanks for the caution. Yes, looks like Cx486DX standard pinout. I cross referenced name differences between Am5x86 and Cx486DX and think I've finished my analysis. I think adapting this adaptor for Am5x86 may be a bit involved. Parenthesis () indicate the Am5x86 naming convention. PGA and QFP grid …

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Re: ECS Elite UM8810PAIO REV:2.1

Posted on 2025-03-31, 06:02

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by feipoa

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

That's a nice looking PCB. If one of these MB's ever lands in my lap, I'll probably assemble the PCB.

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Re: Necessity of TCK, TDI, TDO, TMS pins on Am5x86 and Cx5x86 CPUs?

Posted on 2025-03-31, 04:00

by

by feipoa

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

That's an excellent all-in-one PGA168 comparison of pin assignments for various CPUs. I will be sure to look through it in detail before I alter this QFP208-PGA168 interposer. So far, my observations are as follows: PGA R17 (CLKMUL) -----> QFP 96 (N/C) QFP 11 (CLKMUL) -----> No trace PGA B13 (WB/WT' …

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Re: PcChips M919 - voltage modification the easy way

Posted on 2025-03-31, 03:50

by

by feipoa

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Your comment concerning the existence of a 64 MB module, with the same IC's sparked me to message the seller as well. I have asked for a photo. I want to ensure that they are the same 50 ns 3.3 V Samsung TSOP chips. It was probably me who pointed out that FPM increases performance speed on many 486 …

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Re: Necessity of TCK, TDI, TDO, TMS pins on Am5x86 and Cx5x86 CPUs?

Posted on 2025-03-29, 02:56

by

by feipoa

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I don't know. I didn't emulate the circuit. What circuit? Also, I'm not familiar with the lawsuit details. I just see these 4 pins on, both, Cyrix and AMD's 5x86 datasheets.

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Necessity of TCK, TDI, TDO, TMS pins on Am5x86 and Cx5x86 CPUs?

Posted on 2025-03-29, 01:56

by

by feipoa

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Does anyone know if TCK, TDI, TDO, and TMS are required for Cyrix 5x86 or AMD Am5x86? I have a QFP-to-PGA interposer which contained a defective Cyrix DX2-80 and I want to re-purpose the interposer. However, I noticed that TCK, TDI, TDO, and TMS are not wired. I was hoping not to jumper these 4 pins …

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Re: PcChips M919 - voltage modification the easy way

Posted on 2025-03-28, 20:58

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by feipoa

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Interesting, so the 64 MB modules have the exact same 50 ns IC's? Did the seller send a photo?

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Re: ECS Elite UM8810PAIO REV:2.1

Posted on 2025-03-28, 09:19

by

by feipoa

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Nice work. Are there gerber's hosted somewhere? I've never seen a clip pressing down on the voltage regulator IC like this. How is the clip attached to the PCB and where did you source it? I assume you are using it to press the PQ30RV21 onto the heatsink for cooling purposes? I think you could also …

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Re: Native PS/2 mouse implementation for 386/486 boards using the keyboard controller

Posted on 2025-03-27, 11:43

by

by feipoa

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I recently assembled my first solder-on KBC-PS2 adaptor. With the VIA KBC's at only about $2/each, I felt OK with snipping off all their pins. I'm not sure if I would do this with the more expensive KBC's. I would only do the solder-on if the KBC is behind the ISA slots, as shown here: KBC-PS2_ …

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Re: PcChips M919 - voltage modification the easy way

Posted on 2025-03-27, 04:08

by

by feipoa

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Here's an image of the 128 MB, 50 ns, EDO module I use on my M919. Shown is the front/back of the module. Only this module would allow for the exceptional performance and stability. Perhaps reach out to Memory Masters on eBay to see if they have any more. Filename Magic_M919_128MB_EDO_SIMM.JPG File …

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