Re: ISA DMA issues in DOS with SiS 496/497 based motherboards

Posted on 2023-05-09, 05:45

by

by pshipkov

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I don't feel proud of my contribution to this thread, so thanks for putting up with it. We have to topics mixed-up. 1. My problem that i started the thread with AWE64 Gold having problems in DOS when L1 cache is in WB mode. 2. Your problem, where Yamaha OPL3 based card is having problems at 3x60MHz …

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Re: ISA DMA issues in DOS with SiS 496/497 based motherboards

Posted on 2023-05-08, 07:26

by

by pshipkov

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I had a typo in my last message. Apparently i fixed it a moment before you posted because in your quote it is still WB instead of WT. So yes, i meant if L1 in WT all is good. Will check some other sound cards soon. They work just fine in other rigs with l1wb. So most likely we have a awe64g problem. …

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Re: ISA DMA issues in DOS with SiS 496/497 based motherboards

Posted on 2023-05-08, 00:31

by

by pshipkov

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Ok, i confirm that with L1 in WT the DMA issue is not present. Jumpers are correctly set. Ok, you are looking at the C variants of the motherboard. I am talking about D. Wanted to clarify something else to @Feipoa. He talked about PCI bus divider jumper. At some point i mentioned ISA bus divider, …

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Re: 3 (+3 more) retro battle stations

Posted on 2023-05-07, 21:27

by

by pshipkov

in Marvin \ System Specs

in Marvin \ System Specs

Ah, that is a great point. Not sure why i didn't think of it, since we put good effort to determine it for the VLI board. Thanks for the reminder. Going to try this now.

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Re: ISA DMA issues in DOS with SiS 496/497 based motherboards

Posted on 2023-05-07, 21:26

by

by pshipkov

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

@mkarcher Thanks for the notes. Your message prompted me to find my notes. You are right, TWEAKS.EXE does not allow dynamic change of the L1 cache policy. Setting L1 cache in WT mode DOES solve the DMA problem with AWE64G. My initial statement was incorrect. Will empirically verify it soon to …

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Re: 3 (+3 more) retro battle stations

Posted on 2023-05-07, 21:17

by

by pshipkov

in Marvin \ System Specs

in Marvin \ System Specs

Thanks for the link. 3x66 results in no lights here with the PVI board. Most likely related to the fact that the motherboard has options for 3.45V and 3.6V only, which is insufficient for Am5x86 to work at 200MHz. At least i don't have a CPU that can do it at below 4 volts.

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Re: ISA DMA issues in DOS with SiS 496/497 based motherboards

Posted on 2023-05-07, 08:45

by

by pshipkov

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

No, not really.

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Re: ISA DMA issues in DOS with SiS 496/497 based motherboards

Posted on 2023-05-07, 07:48

by

by pshipkov

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

In the most recent case it happens on Lucky Star LS-486E C1/C2/D motherboards with SB AWE64 Gold and Am5x86 processor. Often use TWEAKS.EXE to adjust L1 policy and other parameters. But can be through jumpers as well.

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Re: 3 (+3 more) retro battle stations

Posted on 2023-05-07, 03:34

by

by pshipkov

in Marvin \ System Specs

in Marvin \ System Specs

@CoffeeOne Asus PVI-486SP3 1.22 is unstable at 4x50. It is the motherboard itself. Cannot find jumper config for 60/66. Need to pull the oscilloscope, figured i should ask you if you know.

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Re: ISA DMA issues in DOS with SiS 496/497 based motherboards

Posted on 2023-05-07, 03:32

by

by pshipkov

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Exiting Win back to DOS does not help.

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ISA DMA issues in DOS with SiS 496/497 based motherboards

Posted on 2023-05-07, 02:02

by

by pshipkov

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Been on my mind for a while to ask the local experts about a peculiar issue i am noticing on some SiS 496/497 motherboards. Basically, at least some sound cards will hang the system because at the moment their DMA access is initiated through them. Disabling the internal CPU cache fixes the problem. …

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Re: 3 (+3 more) retro battle stations

Posted on 2023-05-06, 23:58

by

by pshipkov

in Marvin \ System Specs

in Marvin \ System Specs

@WJG6260 Spent some more time with this board. Pretty convinced it cannot go past the 40MHz, unfortunately. I don't think i am missing jumpers config at this point. At the same time this guy here , which is based on the SX variant of the chipset, ticks at 60MHz on a narrow overclock (system is …

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Re: MPEG-1 decoder add-on board for [S3 Vision 968] Diamond Stealth 64 VRAM VLB

Posted on 2023-05-06, 07:27

by

by pshipkov

in Marvin \ Video

in Marvin \ Video

Just remembered something - disabling hidden refresh (decoupled refresh) can potentially improve on visual artefacts in some cases. Did you try that ?

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Re: 3 (+3 more) retro battle stations

Posted on 2023-05-01, 23:10

by

by pshipkov

in Marvin \ System Specs

in Marvin \ System Specs

Ok, you are step ahead with measuring fregs. Same result here if JP9 is in 1-2 position things are not working. So it looks like even the clockgen is producing the higher frequency, the board is not handling it well. It will be bad if that's the case. Was hoping for 386/VLB mobo that goes higher on …

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Re: 3 (+3 more) retro battle stations

Posted on 2023-05-01, 06:55

by

by pshipkov

in Marvin \ System Specs

in Marvin \ System Specs

Thanks a lot for the datasheet. Appreciate it. Quickly skimmed through it. Diagram i got checks-out. Also, 50, 66 and 80 MHz is an option indeed. But the wiring of that motherboard is still a puzzle to me. I also found the 16 and 25 MHz options by trial and error. The interesting part is that i can …

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Re: 3 (+3 more) retro battle stations

Posted on 2023-04-30, 05:16

by

by pshipkov

in Marvin \ System Specs

in Marvin \ System Specs

@WJG6260 Thanks for the additional notes and tests. It really looks like a decent implementation with less than ideal PCI graphics performance. --- @CoffeeOne I remember seeing comments from at least 1 or 2 members here who also run their PVIs with tightest BIOS timings. There are 64Mb FPM RAM …

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Re: List of VLB IDE Controllers

Posted on 2023-04-29, 22:57

by

by pshipkov

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

ADI/2 controllers usually hit 10Mb/s in synthetic tests when inserted in fast motherboards with good BIOS microcodes. Are you using the M919 board ?

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Re: List of VLB IDE Controllers

Posted on 2023-04-27, 20:23

by

by pshipkov

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Appian ADI/2 and many other drivers were attached in previous posts.

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Re: 3 (+3 more) retro battle stations

Posted on 2023-04-27, 16:32

by

by pshipkov

in Marvin \ System Specs

in Marvin \ System Specs

Great info thanks. Been waiting for this one. (Linked from the directory in the first page. Updated the 486 "charts".) An unusual assembly indeed. High level of integration, next gen (for 486) caching techniques. Very strong on paper (thanks for the datasheet). But interactive graphics perf is …

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Re: 3 (+3 more) retro battle stations

Posted on 2023-04-26, 18:51

by

by pshipkov

in Marvin \ System Specs

in Marvin \ System Specs

You are welcome. Effort was fueled by the same interest. I share similar observations. Early 386 hardware, before and around 1991 is too clunky. Late designs - these very compact, budget motherboards, are too restricted. Cost cutting took its blood. The period between late 1991 - early 1993 is where …

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