What chipset are you using? Is it listed in the links below?
http://ibm-pc.org/drivers/unsorted/memory-1/memory-1.htm
http://ibm-pc.org/drivers/memory/memory.htm

Don't be surprised that himem.sys complains it can't find extended memory, because you don't have extended memory. XMS is memory available to the CPU directly (thus not the 2MB of EMS you added because that's not directly accessible) situated above 1MB. You don't have any of that.

nemail wrote:

- Would EMS even be used by any software except games which specifically ask for EMS?

Of course, by Lotus 1-2-3, some disk caching utility or a RAM drive 🤣

AutoSkecth 3.x for DOS also supports EMS. Windows 3.0 in Real-Mode, does, too.

In fact, quite a few games from say, '89 to '94 will require EMS or will at least support EMS optionally, if available.
WingCommander. Keen 4, Lollypop, re-releases of Sierra games with SCI0 or later engines (such as Space Quest 3).

By the way, for EMS 3.2, there also existed some LIMulators that used the HDD as a storage medium.
These were useful for Lotus 1-2-3, for example.

Edit: I'm still surprised that the mainboard doesn't support XMS.
So far, any PC with 1MB supported at least 384k of extended memory.
My Schneider Tower AT, for example, has the same 512/512 and 640/384 options.

Maybe the A20 gate is defective ? If it is, maybe it's worth checking the keyboard controller.
It's often located near the barell battery - next to lake Acid in the land of destruction.. 😉
- If some of its pins have signs of oxidation, this migh be the culprit.

Anyway, it shouldn't hurt to try DR-DOS 6 or Novell DOS 7, too.
They both come with enhanced 286 support and a more complete XMS driver.
Maybe A20 can also be activated by the chipset directly (if supported by DR-DOS).

gdjacobs wrote:

What chipset are you using? Is it listed in the links below?
http://ibm-pc.org/drivers/unsorted/memory-1/memory-1.htm
http://ibm-pc.org/drivers/memory/memory.htm

That looks like a very useful site. Bookmarked. Thanks.

Hi

thanks for your answers and sorry for the delay!

gdjacobs wrote:

What chipset are you using? Is it listed in the links below?
http://ibm-pc.org/drivers/unsorted/memory-1/memory-1.htm
http://ibm-pc.org/drivers/memory/memory.htm

I have this board, any idea please which chips are the chipset? Should be high-res enough to read all the names on the ICs

Don't be surprised that himem.sys complains it can't find extended memory, because you don't have extended memory. XMS is memory available to the CPU directly (thus not the 2MB of EMS you added because that's not directly accessible) situated above 1MB. You don't have any of that.

I was afraid that this was the case.

Of course, by Lotus 1-2-3, some disk caching utility or a RAM drive 🤣

Don't need any of this, unfortunately 🤣

AutoSkecth 3.x for DOS also supports EMS. Windows 3.0 in Real-Mode, does, too.
In fact, quite a few games from say, '89 to '94 will require EMS or will at least support EMS optionally, if available.
WingCommander. Keen 4, Lollypop, re-releases of Sierra games with SCI0 or later engines (such as Space Quest 3).

Windows 3.0 and games would be the most likely usecase for me, I guess. Windows runs quite well on this machine. And I've stumbled upon some games which require EMS earlier.

By the way, for EMS 3.2, there also existed some LIMulators that used the HDD as a storage medium.
These were useful for Lotus 1-2-3, for example.

Saw those, must be blazing fast 🤣

Edit: I'm still surprised that the mainboard doesn't support XMS.
So far, any PC with 1MB supported at least 384k of extended memory.
My Schneider Tower AT, for example, has the same 512/512 and 640/384 options.

My board is configured via Jumpers and BIOS. Jumper and BIOS settings have to match, otherwise it complains "memory error" during boot.
Jumper options are: 256KB, 512KB, 640KB, 768KB and 1MB.
BIOS options are: Memory below 1 Meg and Memory above 1 Meg.
Regardless of what I do, if I want to have 640KB below 1 Meg, there won't be any memory available above 1 Meg.
So I can do like 512K/512K or 640K/0K. The board is fully populated so it has 1MB installed physically.

Maybe the A20 gate is defective ? If it is, maybe it's worth checking the keyboard controller.
It's often located near the barell battery - next to lake Acid in the land of destruction.. 😉
- If some of its pins have signs of oxidation, this migh be the culprit.

I was very lucky, there are absolutely no signs of corrosion on the board, it looks like brand spanking new.

Anyway, it shouldn't hurt to try DR-DOS 6 or Novell DOS 7, too.
They both come with enhanced 286 support and a more complete XMS driver.
Maybe A20 can also be activated by the chipset directly (if supported by DR-DOS).

Problem is, that there isn't any XMS memory if I want to have 640k of conventional memory...

That looks like a very useful site. Bookmarked. Thanks.

Indeed, thanks!

I have a VERY similar board, only with additional FDC on board. I think indeed the best way here is to set it to 1 MiB below, and if you really NEED more memory to use an EMS card. Very few software needs XMS, and running Windows on this machine in standard mode wouldn't be much fun. This is also why I have another Suntac based board with 2MiB (max 4MiB) of RAM. This runs Windows 3.1 really fine.

Your board and mine are really ancient, and I would suggest just to use it as a fine and nice DOS game machine from the 80s. Because it is probably from way before 1990... It is also not using any highly integrated chipset such as Suntac, Neat or the like. It is all discrete components, as you can tell from the insanely high component count...

root42 wrote:

I have a VERY similar board, only with additional FDC on board. I think indeed the best way here is to set it to 1 MiB below, and if you really NEED more memory to use an EMS card. Very few software needs XMS, and running Windows on this machine in standard mode wouldn't be much fun. This is also why I have another Suntac based board with 2MiB (max 4MiB) of RAM. This runs Windows 3.1 really fine.

Your board and mine are really ancient, and I would suggest just to use it as a fine and nice DOS game machine from the 80s. Because it is probably from way before 1990... It is also not using any highly integrated chipset such as Suntac, Neat or the like. It is all discrete components, as you can tell from the insanely high component count...

You mean 640k below 1M? Don't think 1M below 1M will work or do anything... (can't remember whether I tried it or not, though)...
EMS card is built up and inserted already so as I don't have any use for it in another system, I'll leave it in this build - don't have to load the driver if i don't need it...

Windows 3.0 actually runs quite well, no worries whatsoever.. I wanted XMS to be able to load high some TSRs and drivers, to free up conventional memory even more. Even if I have 640k/0k, there are only about 550k to 570k free when drivers like mouse, CD, doskey and so on are loaded. I already did use very slim drivers like ctmouse and I did make a config.sys boot menu as well to choose which drivers I need but still, having everything loaded high and keeping conventional memory free would be really nice.
I know that this is a veeery old board and keeping it as a really old early 80ies DOS machine with 640k/0k is an option (i have more than enough other machines) but still I'd like to try what's possible to achieve with this until I "give up".

Maybe some soldering and wiring up memory directly or something would help? I'm quite good at soldering but I have no idea of the architecture and therefore where to start...

In this kind of machine I would refrain from doskey. And do you really need a CD ROM?

root42 wrote:

In this kind of machine I would refrain from doskey. And do you really need a CD ROM?

why? 😀
cd-rom is more convenient than 3,5" or 5,25" floppies (got both drives in this machine) and the driver isn't as fat as the zip 100 parallel port driver (don't know whether it'd even work on a 286).
i have loads of games and programs archived on CD and it is easier to just whack the cd in, fire up norton commander and extract it directly from cd than doing this on the pc, copying it to floppy and then putting that floppy to the 286.

in reality, it all doesn't really matter anyway. i don't "need" any of all this, I'd just like to try out what's possible. tinkering around is what is fun for me. mostly, when I finished a build, I play one of the same 20 games for a couple of hours and that's about it 🤣

nemail wrote:

I have this board, any idea please which chips are the chipset? Should be high-res enough to read all the names on the ICs

286_10_512.jpg

Now that's funny! I had a similar looking 286 mainboard once! 😁

It had 256KiB of RAM and ran PC-DOS 3.3!
Heck, even Digger was playable @8 MHz! 😁

After double checking I must say that mine seems more modern with a CHIPS chipset:

But it also has this weird 512/512 split of the memory.

Thanks for the picture! Looks neat! 😉

It's a bit ironic, though, that we (including me) consider the OP's board as an oddball.

In reality, this board behaves "sane" or logical.
It uses a linear or contingous memory layout as some computer person of another platform would expect:

The board interprets "no memory remapping" the correct way -> the whole 1024KiB are in order. No gaps.

This is in contrast to most x86 folks who consider "no memory remapping" as 640KiB+384KiB of nothing+384KiB of extended memory
and "with memory remapping" as 640KiB+384KiB of upper memory (which is the normal way of describing it on x86 or PC/AT).