Re: XT clone motherboard repair advice/help needed (KT 10 M/B)

Posted on 2019-04-11, 21:17

by

by HanJammer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

First check if /CE (pin 20) is not actually tied to ground permanently. Well, it's definitely shorted to the ground (no matter if I test it on EPROM's socket or one of the ground on the PSU for example). I removed EPROM from socket and this pin is still shorted to ground. Possibly only the /OE is …

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Re: XT clone motherboard repair advice/help needed (KT 10 M/B)

Posted on 2019-04-11, 15:07

by

by HanJammer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

First question, when you assembled the probe, did you use 1 or 2 LEDs in series for each color? With just 1 LED and 5V it's possible both colors will shine even if the probe tip is not connected to anything. Depends on the LEDs used (their forward voltage drop to be precise). If you have this issue …

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Re: Bought these (retro) hardware today

Posted on 2019-04-11, 12:02

by

by HanJammer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Merovign wrote: (looks at my craigslist "free" section) Cat (tempting). 🤣 🤣 🤣

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Re: XT clone motherboard repair advice/help needed (KT 10 M/B)

Posted on 2019-04-11, 01:45

by

by HanJammer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Which pins should I use with this tester? All of the BIOS ROM ones, only the populated socket (for now). Test the power delivery pins as well, this is helpful because it validates the result, makes sure the chip is properly powered, and also lets me know which LED color is what signal level. OK, I …

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Re: need idea: what can i do with a 286?

Posted on 2019-04-10, 23:11

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by HanJammer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Yeah, probably will "do it" on my 386 DX-40 build. That's a tad too choppy for my taste especially when the enemies and smoke effects start to move on screen. Also, my 286 is only a 12MHz model. DX40 will be perfect. I remind playing Darker Demo on DX40s at school. Oh, and smoke effects are kinda …

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Re: need idea: what can i do with a 286?

Posted on 2019-04-10, 21:23

by

by HanJammer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Patrick Aalto's LineWars II gone freeware few years ago - and it's one of the more playable space shooters which runs fine on 286s! http://linewars.patrickaalto.com/ Still I think Darker is the best looking game for 286 - it even has short video scenes. It has very specific atmosphere and cool …

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Re: need idea: what can i do with a 286?

Posted on 2019-04-10, 21:11

by

by HanJammer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Patrick Aalto's LineWars II gone freeware few years ago - and it's one of the more playable space shooters which runs fine on 286s! http://linewars.patrickaalto.com/ Still I think Darker is the best looking game for 286 - it even has short video scenes. It has very specific atmosphere and cool …

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Re: need idea: what can i do with a 286?

Posted on 2019-04-10, 15:42

by

by HanJammer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Treat the 286 as a faster XT. Its the bees knees for raw dos. Throw in a SoundBlaster 2.0 and Play some low end dos games on it. Dig out Ultima III or IV! yes the 286 is well faster than xt, i estimate a 286-16 with 0wait to be 5-6 times as fast as xt. however it doesn't have more ram than xt to …

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Re: need idea: what can i do with a 286?

Posted on 2019-04-10, 15:33

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by HanJammer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

286s are so much fun! Much more interesting than 386s which are not really that different than later platforms (basically everything prior to x86-64). Think about limitations of 286 as something that stimulates creativity. Actually you can play most games released before 1993 and even some later …

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Re: XT clone motherboard repair advice/help needed (KT 10 M/B)

Posted on 2019-04-10, 13:29

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by HanJammer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Will do. I will a couple of day though… I also found a local source of dirt chip AMD 8088-2s (like a 3 USD per piece).

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Re: Bought these (retro) hardware today

Posted on 2019-04-09, 22:25

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by HanJammer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Todays haul… All but the first Octek Fox M works fine (even HDDs). But this motherboard is not beyond repair - boots but reports CMOS error... Nice..! You really seem to be interested in the same stuff I am :cool: Good we dont live in the same area :lol: :D Yup, and it's getting worse… I wasn't …

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Re: Bought these (retro) hardware today

Posted on 2019-04-09, 17:06

by

by HanJammer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Todays haul… All but the first Octek Fox M works fine (even HDDs). But this motherboard is not beyond repair - boots but reports CMOS error...

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Re: XT clone motherboard repair advice/help needed (KT 10 M/B)

Posted on 2019-04-08, 23:41

by

by HanJammer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Yeah, I followed this thread for a while… Which pins should I use with this tester? I think I also can source some 8088-2 I've seen some cheap on local auctions...

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Re: Looking for manual or jumper settings for Microscience MFM hardcard

Posted on 2019-04-08, 23:25

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by HanJammer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

So it runs! I found some time to play around with it. I checked all 16 dip switch settings, and I noticed that in some cases error message changes from "Error initializing hard drive controller 0" to "Error encountered initializing hard drive 0". Bascially changing all jumpers to their opposite …

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Re: XT clone motherboard repair advice/help needed (KT 10 M/B)

Posted on 2019-04-08, 22:10

by

by HanJammer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Yeah, I switched them (I've tried both modes). No output. I replaced the 4,7uF caps with 10uF caps, but nothing have changed.

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Re: XT clone motherboard repair advice/help needed (KT 10 M/B)

Posted on 2019-04-08, 20:54

by

by HanJammer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

At the moment I don't have any EEPROMs or FLASH. I only have OTP and UV EPROMs. Only 27256. Also I noticed that now it does this crazy thing almost every time I start it (currently with the AWARD ROM). Edit: nevermind, it won't do this again… I guess it's recap time. I will replace 4,7uF tantalum …

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Re: XT clone motherboard repair advice/help needed (KT 10 M/B)

Posted on 2019-04-08, 20:36

by

by HanJammer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

It seems that with Ruud's diag rom it does this crazy thing with POST codes everytime I start it. This behaviour is different than observed with the original AWARD BIOS or with Supersoft diag ROM (when it only did it once in a while). It will do the same thing without BIOS ROM too. It won't do this …

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Re: XT clone motherboard repair advice/help needed (KT 10 M/B)

Posted on 2019-04-08, 13:15

by

by HanJammer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

OK, I indeed set the output on the card to colour composite and left the dip switches alone. I will try that. I didn't found any jumpers on the board or missing components but I will inspect again and also post better quality photos. CPU is Siemens 8088-2 (8MHz).

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Re: XT clone motherboard repair advice/help needed (KT 10 M/B)

Posted on 2019-04-08, 08:59

by

by HanJammer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

You are lucky and all ICs are on socket. Turn on without BIOS and CPU. What happens? Then remove all other ICs one after one and see if the Sound disappears. Did you check for shorts on the bottom side? Like I said before did visual check and found one bent pin (resistor's pin) which was touching …

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Re: XT clone motherboard repair advice/help needed (KT 10 M/B)

Posted on 2019-04-08, 01:18

by

by HanJammer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I burned and used this one " U33 image for a 27256 EPROM (or 27C256) in a MK36000/27256 adapter ". I used CGA (from the same machine as the motherboard) multi i/o card - I tested it in another PC (I was surprised quite good quality for composite output acutally!): 56426998_2644757562206249_ …

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