P-III only stable with In-order Queue Depth=1 - 440BX Tualatin slotket mod

Posted on 2019-09-19, 04:49

by

by nztdm

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

So, I've collected a bunch of old parts, and am in the process of finishing up a DOS+Win98 gaming PC build. Specs: A-bit BE6-II rev1.0 (BIOS 70) NVIDIA FX-5700LE AWE64 Value PCI Fast Ethernet PCI USB2.0 (ALi) MSI MS-6905 Master 2.3 Slotket With a P-III Coppermine (667/133/256), all is well. With a …

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Re: Help identifying 386DX motherboard

Posted on 2019-08-15, 23:44

by

by nztdm

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Looks to be this: https://arvutimuuseum.ee/th99/m/M-O/30236.htm And unfortunately not this: https://arvutimuuseum.ee/th99/m/E-H/30804.htm Probably not suitable for 40MHz and lots of RAM/cache? It doesn't have the 28-pin sockets for 32Kx8 TAG SRAMs.

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Help identifying 386DX motherboard

Posted on 2019-08-15, 23:00

by

by nztdm

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Hello Same ol same ol.. help me identify a 386 mobo with no branding. I'll trawl through TH99 images later, but just checking if anyone knows. FYI: It's a board I may purchase. I wanted a suped up 386. I see a desirable chipset. It has 33MHz CPU installed, but I only see a 50MHz oscillator, which I …

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Re: NuXT - MicroATX Turbo XT Motherboard - 9.55MHz, UMBs, XT-CF, SVGA, HD Floppy, Serial

Posted on 2019-07-14, 09:06

by

by nztdm

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

The horizontal connector can be a problem if a picoPSU is connected, since there is no space below for the cables that exit from it. Very cool, just curious why did you lay the power connector horizontal? Thanks :) And because I like the look of a side-entering ATX connector more. This board is not …

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Re: NuXT - MicroATX Turbo XT Motherboard - 9.55MHz, UMBs, XT-CF, SVGA, HD Floppy, Serial

Posted on 2019-07-11, 09:47

by

by nztdm

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

If you need a mouse converter you can use this one: https://github.com/matze79/PS2-Adapter Its a project running since 2015 and has made a bit of progress. Its running very well. Also supports 19200 Baud mode in DOS to speed up Mouse trough KVM (Lag reduction) https://www.vogons.org/viewtopic.php …

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Re: NuXT - MicroATX Turbo XT Motherboard - 9.55MHz, UMBs, XT-CF, SVGA, HD Floppy, Serial

Posted on 2019-07-11, 03:11

by

by nztdm

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Hello The only things that can conflict in the upper memory area is device RAM such as EMS cards or network cards, and ROMs. The RAM in the upper memory area you've allocated, is there for you to use. Put your sound driver there (do you need a sound driver?). Note how I say "the RAM in the upper …

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Re: NuXT - MicroATX Turbo XT Motherboard - 9.55MHz, UMBs, XT-CF, SVGA, HD Floppy, Serial

Posted on 2019-07-10, 21:05

by

by nztdm

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

If you look at the Upper Memory Map in the manual, VGA RAM isn't there. Only the VGA BIOS is there, which shares the same area as UMB switch 1. So if you have no other cards installed that have a BIOS extension or use upper memory, you can turn on switches 2 through 6. You can then configure it with …

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Re: NuXT - MicroATX Turbo XT Motherboard - 9.55MHz, UMBs, XT-CF, SVGA, HD Floppy, Serial

Posted on 2019-07-10, 08:02

by

by nztdm

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I've written a small NuXT user manual. Some of the info is redundant as it's on the PCB too, but it's clearer in the manual. https://github.com/monotech/NuXT/blob/master/ … er%20Manual.pdf Feel free to let me know if there's any mistakes or things you think should be added. Cheers

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Re: NuXT - MicroATX Turbo XT Motherboard - 9.55MHz, UMBs, XT-CF, SVGA, HD Floppy, Serial

Posted on 2019-07-07, 04:27

by

by nztdm

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I am not planning on adding a second hard drive, just an optical drive. I figured the IDE controller on the ESS card probably wasn't going to work for that. I was planning on get the IDE controller on your website as some point for the optical drive. Would that require an edits to the ROM image as …

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Re: NuXT - MicroATX Turbo XT Motherboard - 9.55MHz, UMBs, XT-CF, SVGA, HD Floppy, Serial

Posted on 2019-07-07, 03:55

by

by nztdm

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I got my board in yesterday :D. Just getting setup now, thought I would share some pictures. I ended up getting the full tricked out version with 512kb of VRAM and the 8087 math coprocessor. I am very happy to hear you like it! That looks nice in that case. Some tips: There is no 3V on this board. …

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Re: NuXT - MicroATX Turbo XT Motherboard - 9.55MHz, UMBs, XT-CF, SVGA, HD Floppy, Serial

Posted on 2019-06-16, 06:24

by

by nztdm

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Assembled boards and DIY kits are back in stock here: https://monotech.fwscart.com/NuXT_-_MicroATX_ … 4_19777986.aspx

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Re: NuXT - MicroATX Turbo XT Motherboard - 9.55MHz, UMBs, XT-CF, SVGA, HD Floppy, Serial

Posted on 2019-06-12, 05:50

by

by nztdm

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

BloodyCactus wrote: Id rather see far less noise on the isa bus / power rails. maybe next revision. What do you mean? I haven't taken any readings for this revision. The board has gone to 4 layers with separate GND and VCC layers.

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Re: NuXT - MicroATX Turbo XT Motherboard - 9.55MHz, UMBs, XT-CF, SVGA, HD Floppy, Serial

Posted on 2019-06-12, 01:53

by

by nztdm

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

There is this PS/2 to XT Keyboard Converter that I build. https://monotech.fwscart.com/PS2_to_XT_Keyboard_Converter/p6083514_19714002.aspx Out of stock until I get around to drilling the enclosures for the next batch. I do plan on a PS/2 to Serial Mouse converter box at some stage, that can …

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Re: NuXT - MicroATX Turbo XT Motherboard - 9.55MHz, UMBs, XT-CF, SVGA, HD Floppy, Serial

Posted on 2019-06-10, 22:58

by

by nztdm

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I'd love to see you implement a PS/2 to serial mouse converter next. I've heard of some efforts doing that before but I don't know how successful it was. Working on that one myself. I've been writing PS/2 host/device code since Friday. Almost done with the hardware layer, then just need to …

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Re: NuXT - MicroATX Turbo XT Motherboard - 9.55MHz, UMBs, XT-CF, SVGA, HD Floppy, Serial

Posted on 2019-06-07, 00:53

by

by nztdm

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

That is the most beautiful thing I have ever seen this morning. LOL Somebody with significantly better FPGA skills than me needs to get in there and clone those ICs. What's the story on the BIOS? Was it hand-crafted or ported from some existing hardware? Glad you like! Go to the first link in the …

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Re: NuXT - MicroATX Turbo XT Motherboard - 9.55MHz, UMBs, XT-CF, SVGA, HD Floppy, Serial

Posted on 2019-06-06, 14:17

by

by nztdm

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

BinaryDemon wrote: Very cool, just curious why did you lay the power connector horizontal? Thanks 😀 And because I like the look of a side-entering ATX connector more. This board is not as wide as MicroATX boards can be, so there is plenty of space in a MicroATX case.

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Re: NuXT - MicroATX Turbo XT Motherboard - 9.55MHz, UMBs, XT-CF, SVGA, HD Floppy, Serial

Posted on 2019-06-06, 13:36

by

by nztdm

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I love this. Any hope for a 3D printed I/O shield? Glad you like it! I don't have 3D modelling experience, but could give dimensions to someone that does, or they can look at the gerber files. You can get blank metal I/O shields on eBay. Would need laser cutting machinery for those.. or d-sub …

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Compaq Portable RAM Decoder PROM replacement

Posted on 2019-06-06, 13:23

by

by nztdm

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Hello I recently acquired a Compaq Portable, and have finished restoring it to full working order. In the process of doing that, I upgraded the onboard RAM from 256K to 640K. This is an offically supported upgrade by Compaq, but requires a replacement Bipolar PROM for memory decoding (U35 on …

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NuXT - MicroATX Turbo XT Motherboard - 9.55MHz, UMBs, XT-CF, SVGA, HD Floppy, Serial

Posted on 2019-06-06, 13:15

by

by nztdm

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Hello all I've designed a MicroATX XT motherboard based on Sergey Kiselev's Micro 8088 SBC and ISA cards as seen here: http://www.malinov.com/Home/sergeys-projects Can be used as a full featured XT without any cards. https://i.imgur.com/i5K5GBA.jpg https://i.imgur.com/HttqWjP.jpg https://i.imgur.com …

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Re: How do you select replacement capacitors? (For Compaq Portable 2)

Posted on 2019-05-12, 01:52

by

by nztdm

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Hey nztdm. I'm not sure I'm following forum rules or whatever. Just a quick question. I see you're a veteran on SLT/286 psu. Following three burnt capacitors on it, I'm currently on my fourth. For the first time I'm stumbled cause I'm not sure which capacitor it was before it blew beyond …

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