Re: Need some help identifying this 486 VLB motherboard

Posted on 2021-04-27, 16:57

by

by whitepawn

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Does this card posts?Maybe post code will identify manufacturer of board. Also cache seems fake, i may be mistaken. Cipset seems ALI but there is 5v-3v sticker i am also not sure. Edit:Nevermind you never powered board.

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Sound Problem on Socket 3 Single Board Computer

Posted on 2021-03-28, 10:00

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by whitepawn

in Marvin \ Sound

in Marvin \ Sound

Hi, I recently resurrected a SBC (https://www.vogons.org/viewtopic.php?f=46&t=80048) with Cyrix DX2-66 cpu and 16 Mb RAM.Used XTIDE on an intel network card (https://www.vogons.org/viewtopic.php?f=46&t=79986) and installed Windows 98 SE on 8Gb hard drive.Everything went somoothly and system booted …

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Re: Intel S82595FX and 3com 3C905B XTIDE Boot Problem

Posted on 2021-03-25, 16:03

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by whitepawn

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Ok i managed to work Intel S82595FX with PMC PM29F002 which is a only 5v flash chip.I have erased chip first and readed empty 256KB file for padding.Then downloaded XTIDE bios and configured it with xtidecfg.com. Inserted configured bios to padded file many times (I am not sure if this is required.) …

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Re: Documentation / BIOS Intel SBC386AT25 Board

Posted on 2021-03-24, 14:39

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by whitepawn

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Ok here is what i mean.It is not complicated come on :) rsz_img_20210324_173213.jpg "with disabled check id" or another parameter will not help in your case. Red and black wires are going to external adjustable power supply.Of course my chip is 32 pin you have to adapt to 28 pin. Since bios is …

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Re: Documentation / BIOS Intel SBC386AT25 Board

Posted on 2021-03-24, 13:38

by

by whitepawn

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Attached BIOS from my mobo, but U79 seems to be broken, every time I reread the chip on TL866 I have a new value :( It seems your eprom corrupted but maybe there is a way to read it.Just lower the VCC and VPP slightly.You need to lift VCC(Pin28) and VPP(Pin1) pins from TL866 and feed the chip with …

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Re: Octek Jaguar II missing cache .

Posted on 2021-03-23, 22:23

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by whitepawn

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Maybe this helps? Filename 9d435df64822.jpg File size 146.43 KiB Views 197 views Filename 67c0c9609aec.jpg File size 830.92 KiB Views 197 views Source: http://www.motherboards.org/forums/viewtopic. … hp?f=2&t=123047

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Re: PC420-G2 Single board computer manual and Troubleshooting

Posted on 2021-03-23, 21:25

by

by whitepawn

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Ok i figured it out it was a bad solder joint on ALI M1489.I soldered it and cache is detected.Checked with cachechk4: rsz_img_20210323_231143.jpg Also figured out if you use 32 pin instead of 28 pin JP11 and JP12 must be enabled i believe.So it is not relevant in my case since i only have 28 pin …

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Re: PC420-G2 Single board computer manual

Posted on 2021-03-23, 12:07

by

by whitepawn

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Ok I invested a TL866 Programmer and read original chip then i compared it with my PSC-486 bios.Surprisingly it was very similiar to PSC-486 bios only some of bytes are changed so i decided to flash PSC-486 bios and board is booting fine without i/o conflicts or so.I can boot DOS. When i was …

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Re: PC420-G2 Single board computer manual

Posted on 2021-03-20, 15:17

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by whitepawn

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I see, let me check on my board from cpu socket. About JP4 only 1-2 closed gives 80mhz 1-2 and 3-4 closed seems 66mhz on my board. Thanks for testing.Since i don't have an AM5x86 i am unable to test it. Also another info about i/o error i disabled com ports and parallel port no luck. I have searched …

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Re: PC420-G2 Single board computer manual

Posted on 2021-03-19, 08:37

by

by whitepawn

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Yes dx2's are 5v cpu's but works fine with 3.3 volts in my case. My board have LX8385- 00 (which is an adjustable voltage regulator, not fixed) not LT1085 so i expect voltages other than 3.3volts :) Could you measure your board 1-2 closed, 2-3 closed and all open if possible?Maybe my board or …

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Re: PC420-G2 Single board computer manual

Posted on 2021-03-19, 00:48

by

by whitepawn

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Oh i see, a test will be useful. Voltage jumper is: 1-2 closed=3.3v 2-3 closed=3.45 v all open=3.3v from my board. No 5v combinations i have found yet.You can confirm via middle leg of voltage regulator and a multimeter before installing cpu.

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Re: PC420-G2 Single board computer manual

Posted on 2021-03-18, 14:05

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by whitepawn

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Ok i have done my homework. Firstly it wasn't a hardware issue.I managed to work board with Intel DX2 66 Mhz.It was a jumper issue and bios issue.Also here is the interesting thing if i boot system with wrong jumper settings it posts but it gives error "bios rom checksum error".Has anyone ever came …

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Re: Recommendations on soldering services?

Posted on 2021-03-17, 11:23

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by whitepawn

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Actually i never desoldered one but managed to Fix it.If your board PCB has many layers on it, it will be a pain to remove Dallas rtc.I just expose pins Via a dremel in slow speed and solder wires directly.After confirming it works you can seal it with epoxy and black toner mixture. Here is my …

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Re: SBC 486 DX4-100

Posted on 2021-03-17, 07:54

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by whitepawn

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

mt777, I just wanted to confirm jumper settings along with my board thats why i asked for a picture. Most of "486/5x86 SBC ver g6" pictures onlne are have no cpu installed on board and installed ones are covered by a heatsink and also a not known working device. Anyway bios dump will be very useful …

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Re: SBC 486 DX4-100

Posted on 2021-03-16, 22:27

by

by whitepawn

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

mt777, Thanks for reply. It will be very useful, i appreciate if you add photos of your board if possible.

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Re: SBC 486 DX4-100

Posted on 2021-03-16, 18:38

by

by whitepawn

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Hi, It will be a necropost but could you please dump bios file?I have a similiar hardware in this post which i don't have a bios for it. PC420-G2 Single board computer manual and Troubleshooting Thanks in advance.

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Re: PC420-G2 Single board computer manual

Posted on 2021-03-16, 18:36

by

by whitepawn

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I have done my research and found two similiar boards to mine. One of them is "486/5X86 SBC Ver:GC" And the other one is "NAGASAKI IPC Embedded Computer, 960420 GCA, 486/5x86 SBC Ver:GC" aka "NASA-PC420" according to archive.org: https://web.archive.org/web/20000307120159/http://www.nagasaki.com.tw/ …

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Re: PC420-G2 Single board computer manual

Posted on 2021-03-14, 13:41

by

by whitepawn

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Hi, Thanks for your reply. You are absolutely right my bad, i didn't give full information.Let me explain with more details: As i mentioned i have fully working PSC-486, in this board i backed up bios file with uniflash and hotflashed a spare chip (MX28F1000PPC-12C4) with a socket 7 board (Tomato …

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PC420-G2 Single board computer manual and Troubleshooting

Posted on 2021-03-14, 11:54

by

by whitepawn

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Hi, I couldn't help myself and bought another single board computer which labeled as PC420-G2 by protech company. Here is SBC page in 1997: https://web.archive.org/web/19970327052802/http://www.protech.com.tw/ipc420.html IMG_20210313_201133.jpg After cleaning the board, installed another cpu Cx486 …

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Re: UMC UM85C408AF Bios Needed (Included Magic Smoke)

Posted on 2021-03-13, 22:48

by

by whitepawn

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Thank you both for your reply. Since i don't have a eprom or eeprom programmer i have to use uniflash with hotflash method.I have some experience with XTIDE roms via this method.I don't have ant UV eraser also which leads me a flash chip (Intel 28F001BX-T) that i already have from a scrap PII mobo. …

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