Re: Why does EMS suck on my 286?

Posted on 2019-08-12, 13:03

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by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Well, at least we have a working theory of why the EMS doesn't work... I actually don't believe that ISA bus master cannot do 16-bit access to 8-bit memory target on ISA, if this is the theory. The CPU is already a bus master that can do 16-bit access to 8-bit ISA memory target. The chipsets will …

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Re: Why does EMS suck on my 286?

Posted on 2019-08-12, 03:07

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by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

That would be quite an undertaking for me, I wouldn't even know where to start with an assembler (MASM?) What about another utility program that could corroborate what PCCONFIG is saying regarding the memory access bit-width of the page frame? If I could confirm completely that the Above Board only …

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Re: Why does EMS suck on my 286?

Posted on 2019-08-11, 15:34

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by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

A logic analyzer with an ISA card edge would really come in handy right about now. Be so easy to just look for any addresses in the page frame and just peep the high byte of the data bus...

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Re: Why does EMS suck on my 286?

Posted on 2019-08-11, 04:44

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by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I was under the impression that the AHA-1542B actually does bus mastering and does not perform DMA through the 8237. I don't recall seeing anything in the manual that described it using the 8237 either. https://www.tuhs.org/Usenet/comp.unix.sysv386/1991-February/003525.html This site has some pretty …

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Re: Why does EMS suck on my 286?

Posted on 2019-08-11, 03:50

by

by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

No it didn't overlap. That particular informational display only distinguishes regions by timing factor. The description field is unreliable. Any other diag (MSD, Checkit, etc.) showed a distinct 64kB page frame between C800-D7FF and the SCSI ROM from DC00-DFFF

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Re: Why does EMS suck on my 286?

Posted on 2019-08-11, 00:56

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by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I've been trying in vain to successfully get ASPI4DOS.SYS to actually allocate a buffer. Regardless of whether I use the /W or /WM switch it simply loads normally, using the exact same amount of conventional memory it does with no switches, and 0 XMS. I suspect it may be a similar situation to the …

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Re: Why does EMS suck on my 286?

Posted on 2019-08-10, 15:34

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by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Remember the Above Board is a 16-bit card, and it was doing the exact same thing. Unless EMS itself is limited to 8-bit transfers by design? Every time I've tried loading SMARTDRV from the command prompt, it has loaded itself into conventional memory anyway, so I'm not sure the /L switch would do …

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Re: Why does EMS suck on my 286?

Posted on 2019-08-10, 05:19

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by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Is it even possible for ISA DMA to go from one ISA card (SCSI HBA) to another (EMS Board)? I thoroughly cleaned all edge connectors before building this system. I can try moving the SCSI card I guess, but I don't think it's a contact problem.

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Re: Lucky Star LS-486e rev F doesn't recognize ATAPI

Posted on 2019-08-10, 03:29

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by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

the board doesn't need to recognize the drive for it to work, just load VIDE-CDD.SYS and carry on

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Re: Why does EMS suck on my 286?

Posted on 2019-08-10, 03:20

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by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Only one problem - using double buffering is destroying my disk I/O performance, anything I can do about that?

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Re: Why does EMS suck on my 286?

Posted on 2019-08-10, 00:43

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by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

how about using smartdrv with the /double_buffer switch OK we're on to something here! Just running SMARTDRV.EXE from the command prompt fixes the issues with Keen, BioMenace and Spear of Destiny. So I think it's safe to say the problem is in fact disk I/O related. Unfortunately the garbled cockpit …

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Re: Why does EMS suck on my 286?

Posted on 2019-08-09, 20:50

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by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

kjliew wrote: I would suggest one last try with Intel Above Board and setting the EMS Page Frame to CC00 instead of D000. I can but what's the reasoning behind this?

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Re: Why does EMS suck on my 286?

Posted on 2019-08-09, 15:59

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by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Here's the memory map without the EMM driver loaded, clearly showing nothing in the page frame area: Filename 20190808_225526.jpg File size 1.67 MiB Views 525 views Here's the result of TESTEMS: Filename 20190809_115311.jpg File size 1.06 MiB Views 525 views

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Re: Why does EMS suck on my 286?

Posted on 2019-08-09, 14:06

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by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Scali wrote: maxtherabbit wrote: EMS just doesn't work on this system outside of synthetic tests apparently. Which brings me back to my earlier point of the possible limits of these synthetic tests. Sure, it's a good point. I just don't have the DOS ASM chops to write a better test

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Re: Why does EMS suck on my 286?

Posted on 2019-08-09, 12:47

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by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Yes, I ran SETBOARD. I had it set up to provide no conventional or XMS, the entire board was allocated to EMS. It was configured properly at the software level as well. EMS just doesn't work on this system outside of synthetic tests apparently.

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Re: Why does EMS suck on my 286?

Posted on 2019-08-09, 04:30

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by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Just tried loading ASPI4DOS.SYS, both with no switches and with /W and with /WM. No effect

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Re: Why does EMS suck on my 286?

Posted on 2019-08-09, 03:34

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by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

There is no way to restrict the DMA capabilities of the SCSI HBA that I am aware of other than changing the DMA transfer speed. I think you can if you load ASPI4DOS.SYS. The /W or /WM option allocates buffers in extended memory or main memory. There is even /V or /VM that allocates buffer for video …

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Re: Why does EMS suck on my 286?

Posted on 2019-08-09, 02:32

by

by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Maybe the SCSI BIOS cannot transfer data properly from disk to the memory located on the EMS card. Either because of a software bug or hardware incompatibility. Especially if the SCSI card is 16-bit ISA and the EMS card is 8-bit ISA, trying to do DMA in that scenario may not be supported. Is there …

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Re: Why does EMS suck on my 286?

Posted on 2019-08-09, 01:59

by

by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Typically, if the 286 chipsets support ROM shadowing, then it would also come with EMS support. So I think he has a plain vanilla 286 system that simply maps the 4MB memory into 640KB and the remaining 3456KB above 1MB. If the chipsets support ROM shadowing, then it can remap some of those 3456KB …

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Re: Why does EMS suck on my 286?

Posted on 2019-08-09, 01:59

by

by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

How about posting your AUTOEXEC.BAT and CONFIG.SYS? just booted from a freshly made MS-DOS 6.22 floppy disk containing no AUTOEXEC.BAT, and a CONFIG.SYS containing only a single line: DEVICE=LTEMM.EXE /P:D000 Only change in symptoms observed was Spear of Destiny now stops playing the music when it …

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