Re: Memory post count on 1mb xt juko board shows 640k

Posted on 2021-11-06, 13:55

by

by lowlytech

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Thanks for all the input on this board. I do appreciate it greatly. My XT-IDE kit is coming today so hopefully I can start playing with emm drivers and whatnot a bit later today, granted I get time to head out to the garage later. I will see if I can find the Juko branded 2.32 bios out there …

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Re: Memory post count on 1mb xt juko board shows 640k

Posted on 2021-11-06, 12:15

by

by lowlytech

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Finally had a chance to get the board photographed and dumped the BIOS. It's homemade electric tape label over the uv window is less than professional, but this is the way I received it. When I first powered it on the system physically had 768k installed but the memory count still stopped at 640k. …

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Re: Memory post count on 1mb xt juko board shows 640k

Posted on 2021-11-05, 16:00

by

by lowlytech

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I will take a few pictures of the board when i get home tonight. I can confirm both sw3 and sw4 are off. I also tried sw1 to toggle parity and this didn't make any changes either. Other than that i did shuffle the chips around in the existing banks to see if the 640 count was changed, but it didn't …

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Memory post count on 1mb xt juko board shows 640k

Posted on 2021-11-05, 11:58

by

by lowlytech

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I have a variant of the juko baby xt and have 8 44256 chips and 4 mcm6256 chips installed for parity. However the post count only counts up to 640k. Booting the system and running checkit shows 640k as well. I am aware of a driver to load to get the memory betond 640k, but shouldn't the post test …

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Re: CRT tube swap with two similar monitors

Posted on 2021-10-03, 21:37

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by lowlytech

in Marvin \ Video

in Marvin \ Video

Got a chance to get it swapped...and no meltdowns. Everything worked out perfect. The screen was mega stretched, but the controls on the front were within spec to get the size back to normal. This screen is much brighter than the other one. Thanks all for the encouragement to swap this over 20211003 …

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Re: CRT tube swap with two similar monitors

Posted on 2021-10-03, 17:13

by

by lowlytech

in Marvin \ Video

in Marvin \ Video

Good to know. Thanks. will go ahead and give it a try, just didn't know what exactly would happen if something was backwards. You think the ohm difference isn't a big deal between the two tubes?

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Re: CRT tube swap with two similar monitors

Posted on 2021-10-03, 16:22

by

by lowlytech

in Marvin \ Video

in Marvin \ Video

It would seem checking resistance red and blue on both tubes show simliar resistances of only 0.44 ohms, however between yellow and green i get 7.57 ohms on my potential doner and 2.78 ohms on the worn out tube

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CRT tube swap with two similar monitors

Posted on 2021-10-03, 16:12

by

by lowlytech

in Marvin \ Video

in Marvin \ Video

I have 2 Samsung Syncmaster 3 monitors. They are a minor model different, about 8 months apart. One is CVM4967P (Syncmaster 3) and the other is similar but its plastics have turned to crumbled chunks so I don't have its exact model since its outer shell is long gone, but the front shows Syncmaster …

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Re: Need link to DOS utility to reset OPL3/FM

Posted on 2021-10-01, 19:20

by

by lowlytech

in Marvin \ Sound

in Marvin \ Sound

Sounds good. The sound card is a sound blaster CT2940 with genuine Yamaha OPL3 onboard, so it should be good. Thanks so much for confirming.

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Re: Need link to DOS utility to reset OPL3/FM

Posted on 2021-10-01, 17:16

by

by lowlytech

in Marvin \ Sound

in Marvin \ Sound

Thanks Vstrakh, appreciate the program, i will check it out. However if i am wanting to reset FM/OPL wouldn't the port address need to be 388h? Thanks

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Need link to DOS utility to reset OPL3/FM

Posted on 2021-10-01, 03:09

by

by lowlytech

in Marvin \ Sound

in Marvin \ Sound

There was someone here that had wrote a small program to reset the FM/OPL of your sound card if it got stuck after exiting a game. Can anyone repost it here or link to the original post? I have looked all night here and can't find it after googling and browsing through posts here. Thanks in advance …

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Re: BIOS editing/duping for a 486

Posted on 2021-09-14, 19:15

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by lowlytech

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

You ever find a BIOS for your PerComp board? I found this exact HT83C191A board today while at work in a box of stuff. Will test it tonight and see if it POST's. If you still need the BIOS image just let me know. Filename 20210914_135827.jpg File size 1.88 MiB Views 341 views

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Re: Question on component on video card

Posted on 2021-09-12, 21:58

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by lowlytech

in Marvin \ Video

in Marvin \ Video

Well i bypassed that inductor and it didn't change the behavior of the monitor dropping sync. Any other ideas other than the main GPU that would cause the sync to drop in and out?

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Question on component on video card

Posted on 2021-09-12, 04:31

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by lowlytech

in Marvin \ Video

in Marvin \ Video

I have a video card that will loose sync, but does boot up half the time, but before POST finishes, the screen starts flickering and goes out. The system will sometimes resync and the display is there where it left off. I think that the inductor L5 may be bad. This goes to pin 14 on the VGA port. …

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Re: Help with jumpers/documentation on alaris board

Posted on 2021-07-17, 21:44

by

by lowlytech

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Awesome. Thanks Horun for the info you found. Appreciate you very much. I have 4 of the cache chips ordered, once i get them i will give it a shot and see if we can jump to 256k.

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Help with jumpers/documentation on alaris board

Posted on 2021-07-16, 23:36

by

by lowlytech

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Found this board and it is got a 486slc2 clocked at 66Mhz. Board works well but was thinking about upgrading the cache from the installed 128K. I can't seem to find an exact match but seems like the cougar is a close cousin to this board. The socket 3 is the only thing throwing it off as it isn't …

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Re: Which VLB Video Card to Keep?

Posted on 2021-02-03, 02:50

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by lowlytech

in Marvin \ Video

in Marvin \ Video

This topic ended tragically too soon. DNS, any luck with replacing the trident 4000 with the 4400?

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Re: Intel D850gb floppy drive issue when geforce3 installed

Posted on 2021-01-24, 05:06

by

by lowlytech

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

🤣, yeah 850GB would be an impressive space for a floppy. Edited title to avoid further misleading.

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Re: Intel 850gb floppy drive issue when geforce3 installed

Posted on 2021-01-24, 05:04

by

by lowlytech

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Wow, thank you so much Darry for all the bios patches and links. Yes this card has an svideo out i suppose would be nice to keep accessable. The chip is a conexant which has a sub id of bt869, so brooktree would be the correct one probably. Thanks again for all the input and help with this card. A …

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Re: Intel 850gb floppy drive issue when geforce3 installed

Posted on 2021-01-24, 01:40

by

by lowlytech

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Wow, thank you so much Darry for all the bios patches and links. Yes this card has an svideo out i suppose would be nice to keep accessable. The chip is a conexant which has a sub id of bt869, so brooktree would be the correct one probably. Thanks again for all the input and help with this card. A …

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