Re: Why does EMS suck on my 286?

Posted on 2019-08-09, 14:06

by

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

by

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

by

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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Re: Why does EMS suck on my 286?

Posted on 2019-08-09, 00:19

by

by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I'm not loading ASPI4DOS, the SCSI BIOS handles my boot drive and I have no other SCSI devices. I'm going to make another MS-DOS 6.22 boot floppy and just put the LTEMM driver on there and try that one more time. If that fails, I'm going to pull the card and move on. SCSI is infinitely more …

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Re: Why does EMS suck on my 286?

Posted on 2019-08-08, 23:59

by

by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Another data point: all the affected titles run without issues when using the EMM286 LIMulator

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Re: Why does EMS suck on my 286?

Posted on 2019-08-08, 23:41

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by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

that's correct my page frame is D0000h, jumpered on the lo-tech and software configured on the Above Board the SCSI card's BIOS is located between C8000-CBFFF

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Re: Why does EMS suck on my 286?

Posted on 2019-08-08, 23:29

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by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Just had a thought - I'm running an Adaptec 1542B SCSI controller, which uses a form of ISA bus mastering... I wonder if that could be interfering with EMS somehow?

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Re: Why does EMS suck on my 286?

Posted on 2019-08-08, 23:17

by

by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

At this point I can only beg you to believe me that there is not system memory mapped into the page frame, nor anywhere else in the upper memory area. How do you know for sure? I can visually verify there is exactly 4096kB of DRAM on the motherboard, by counting ICs. I have confirmed working/usable …

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Re: Why does EMS suck on my 286?

Posted on 2019-08-08, 21:49

by

by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

That is my theory anyway. So that could be caused by 1 of 2 things: 1) The EMS card works, but somehow writes to the IO ports aren't handled properly, so the page frame can't be moved around. 2) The EMS card works, but its memory is 'hidden' because there is system memory mapped into the page frame …

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Re: Why does EMS suck on my 286?

Posted on 2019-08-08, 21:28

by

by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

On one 286 I had and on 1 386sx I had the systems had a bios option to relocate memory in the himem area into extended ram. Given these units only had 1mb total memory getting an extra 384kb was useful But my experience was that if I installed an ems card it wouldn’t work unless I turned The …

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Re: Why does EMS suck on my 286?

Posted on 2019-08-08, 21:25

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by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I strongly doubt that both cards could be physically defective whist passing all diagnostics, so I suspect it is either an issue with my specific PC or the software I'm using. Which is why I started the thread. If you have suggestions for alternate software to test with, I'd be more than happy to …

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Re: Why does EMS suck on my 286?

Posted on 2019-08-08, 21:01

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by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

There are exactly 4MB of DIP DRAM chips on the motherboard. Filename 20190808_165435.jpg File size 1.05 MiB Views 1613 views

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Re: Why does EMS suck on my 286?

Posted on 2019-08-08, 20:46

by

by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

All physical onboard memory above 640kB is hard-mapped to 1MB and onward for XMS use. If that's not true (no memory hole), it's probably not going to work. The physical memory will clash with the EMS window. Which I expect is what's happening, because why else wouldn't it work? Again, have you …

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Re: Why does EMS suck on my 286?

Posted on 2019-08-08, 20:27

by

by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Again, as mentioned in the OP - both cards pass all diagnostic tests (the Intel Above board comes with it's own utility, and both of them passed TESTEMS as well as the Checkit long test) and the motherboard DOES NOT have any memory relocation settings. All physical onboard memory above 640kB is hard …

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Re: Why does EMS suck on my 286?

Posted on 2019-08-08, 16:30

by

by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

As mentioned in the OP, yes I booted off a MS-DOS 6.22 floppy with no effect on the symptoms observed

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Why does EMS suck on my 286?

Posted on 2019-08-08, 15:23

by

by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I have a 286-12, 4MB 0WS onboard RAM - running PC-DOS 7.1. The motherboard maps all memory above 640kB to XMS, no onboard EMS support whatsoever. Initially I purchased an Intel Above Board, and subsequently built the Lo-Tech 2MB EMS board, but games that use EMS malfunction with either one. I've …

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