EMS on a 286 must be implemented in hardware. Either an expansion card or (preferably) through the motherboard's chipset.

maxtherabbit wrote on 2022-02-25, 01:08:

EMS on a 286 must be implemented in hardware. Either an expansion card or (preferably) through the motherboard's chipset.

Not really, see EMM286 - though it does have certain limitations.

Grzyb wrote on 2022-02-25, 01:24:

maxtherabbit wrote on 2022-02-25, 01:08:

EMS on a 286 must be implemented in hardware. Either an expansion card or (preferably) through the motherboard's chipset.

Not really, see EMM286 - though it does have certain limitations.

if by "certain limitations" you mean "crippling and unusable performance" sure

maxtherabbit wrote on 2022-02-25, 01:08:

EMS on a 286 must be implemented in hardware. Either an expansion card or (preferably) through the motherboard's chipset.

This is the motherboard in question. Am I in luck?

appiah4 wrote on 2022-02-25, 06:48:

This is the motherboard in question. Am I in luck?

Yes, Headland HT12 supports EMS.

Grzyb wrote on 2022-02-25, 07:08:

appiah4 wrote on 2022-02-25, 06:48:

This is the motherboard in question. Am I in luck?

Yes, Headland HT12 supports EMS.

Nice, but how do I enable it? EMM386 won't work for sure. Is this what I need: http://vogonsdrivers.com/getfile.php?fileid=839&menustate=0

EDIT: found a lot of info on DosDays, apparently UMB and EMS together is impossible.. That's fine, I don't have much in the way of memory resident stuff on my 386SX build anyway, just a mouse driver and DOSKEY (which I can live without). However I remember this board having specific options in BIOS to map Upper Memory to UMB or Extended Memory, so maybe that helps with some of the issues? Interesting stuff, worth switching the 386SX out for this board methinks.

appiah4 wrote on 2022-02-25, 10:38:

Grzyb wrote on 2022-02-25, 07:08:

appiah4 wrote on 2022-02-25, 06:48:

This is the motherboard in question. Am I in luck?

Yes, Headland HT12 supports EMS.

Nice, but how do I enable it? EMM386 won't work for sure.

Re: Headland HT12/A 286 chipset: UMB driver?

😄

Other memory drivers can be found here.

Vogon Wiki has an entry for HT12, too.
http://www.vogonswiki.com/index.php/Headland_HT12

But you can also use HT12's EMS Page Frame alone.
Those 64KB can be used as a small UMB for loading drivers into.

It really works, if it works. I've made a video years ago.
Just note that some HT12 derivatives may not have EMS support (Headland HT102 aka G2 GC102) or require modified drivers / modified HT12 drivers..
The situation seems not quite clear, still.
http://www.dosdays.co.uk/topics/Manufacturers/headland.php

https://www.youtube.com/watch?v=lr9KrPNis-Q

https://www.youtube.com/watch?v=DSQCKlhmEq8

https://www.youtube.com/watch?v=XqFSWnMpVic

Edit: PCem (sk) did contain HT12 emulation at some point..
Perhaps it can be used as a testbed for the HT12 utilities.
https://pcem-emulator.co.uk/phpBB3/viewtopic.php?t=3060

Anyway, these are just ideas. I just meant to say that these chipsets may hold surprises for us, still.
Derivatives of the HT12 or other chipsets may or may not have certain features.
It's just not obvious at first glance, because utilities need to enable certain registers in first place.
And without the right utilities or a datasheet, they may not be accessible to us at the moment.

Grzyb wrote on 2022-02-24, 17:18:

True for 7.0 revision 0 True for 7.0 revision 1 a.k.a. PC DOS 2000 But what about 7.10 ? Anybody tried it with a pre-386 machine […]
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maxtherabbit wrote on 2022-02-24, 16:42:

PC DOS 7 will run on anything

True for 7.0 revision 0
True for 7.0 revision 1 a.k.a. PC DOS 2000
But what about 7.10 ? Anybody tried it with a pre-386 machine?

So much data to compile in thread.
Yes , no problems running pc-dos 7 or 7.1/2000 ibm or FreeDos on real 80286 T3100e with 4.3 gb seagate inside(partitioned with overlay)fat32 should work also, I don't recommand mixing the 2 on same drive(fat16 or 32.not both)
I have 1024kb + 4x1mb 30pin simms(I suspect one is faulty as it won't load the win3 or 3.1 gui part of setup) it may also be a incompatibility with PC-Dos, but I don't really think so. Everything else works. Even the low cga one disk windowses .
I had no issues during testing the EMM286 or other expansion mem distribution apps.extended stuf is flaky,runs out fast of mem and no comand line to clear, only reset or cold-reboot.