Some mainboard are unable by design to provide enough room for the EMS window, so you won't get any EMS at all using Windows NTVDM.

Your best bet is to use DOSBox.

Thx.
But the DOS Game SPMBT / SPWW2 (The Steel Panthers series, which I highly recommend and are now available for Windows) runsperfectly on my pc without any tweaking. Would that mean that some dos games don't required EMS memory ?

correct

ok.
I installed and configured dosbox.
However, I have a brand new error message, which I posted on the dosbox forum.

eL_PuSHeR wrote:

Some mainboard are unable by design to provide enough room for the EMS window, so you won't get any EMS at all using Windows NTVDM.

Wait, this is a new thing to me, and it's actually interesting; how is, exactly, the room for NTVDM's EMS limited by mobo design?

From what I gather some motherboards either do not properly allocate the required 384K (the EMS 'window') before the end of the first 1MB of RAM or preallocate that area for onboard resources.

Here's dvwjr's expalantion (I've purposely left out the rest of his information at his request in the other thread):

Problem: Windows NT/2K/XP/2003 NTVDM configured for EMS memory does not make available any EMS memory. The EMS page frame is not […]
Show full quote

Problem: Windows NT/2K/XP/2003 NTVDM configured for EMS memory does not make available any EMS memory. The EMS page frame is not allocated, therefore no EMS memory is available for applications. Changes to the PIF file for the NTVDM or its associated CONFIG.NT file have no effect on providing an EMS page-frame for EMS memory.

Description: The Windows NTDETECT.COM and NTLDR detect and enumerate the system memory map at boot time. The NTDETECT.COM performs an Int 15h/AX=E820h BIOS Query System Address Map (if supported) and NTLDR performs a scan of any Option ROMs installed in the System. This information is consolidated and stored in the System Registry during every boot process. This undocumented data is used to instantiate an NTVDM process combined with other data based on custom parameters stored in a PIF file (Program Information File) associated with the particular NTVDM process.

The creation of the NTVDM process involves the use of this System Registry information to map into the NTVDM virtual address space certain required adapter Option ROMs and adapter Memory-Mapped Input/Output (MMIO) registers in the below 1MB virtual address space. The current conservative practice maps all Option ROMs and MMIO registers detailed in the System Registry into the NTVDM process address space - even though they may have no function in the NTVDM process. Legacy third-party VGA adapters have Option ROMs typically located at the 0xC0000 address, however IBM PS/2 models with planar VGA or adapter VGA Option ROM addresses located somewhere in the 0xC0000-0xE0000 memory region. Certain PS/2 microchannel token-ring adapters also had MMIO registers located exclusively in the 0xC0000-0xE0000 address space. These varying Option ROM addresses help explain the conservative exclusion of so many Upper Memory Block addresses during the NTVDM process creation. The video adapter Option ROMs were required to be mapped into the NTVDM address space at the same under 1MB memory address location as the physical address the video adapter occupied at boot time. The allowed for the NTVDM emulation process to allow the video adapter ROM to have exclusive access to most I/O ports for video mode control for VGA and VESA graphics.

The System Registry also identified either PS/2 ABIOS or PC/AT-style extended BIOS support typically located at the 0xE0000-0xF0000 memory address region. The expected PC/AT or PS/2 BIOS 64kB segment located at 0xF0000-0x100000 is also enumerated in the System Registry as an excluded memory region. All of these ROM locations or MMIO registers are excluded from availability as Upper Memory Blocks in the NTVDM virtual memory address space and are the reason for the lack of address space for the location of a 64kB EMS page-frame.

The rest of the thread goes into detail on how to modify your registry to get around this.

The other solution we were doing before this was to disable integrated hardware on the motherboard or to remove PCI devices to free up some space. This worked but was pretty much just a side effect.

Is it easier to run DosBox than to modify the System Registry ?

I'm asking cuz configuring DosBox isn't exactly simple 😊

It's far easier and safer to use DosBox than to be messing around with your registry.

Using DosBox is far easier than trying to get the games to work on a real machine in most cases.

If you really must use NTVDM and do not want to use DosBox for some reason and you do not feel like disabling devices in your BIOS or modifying your registry then you can also use EMS Magic:

Topic 14967

Would have mentioned it earlier but I only recently found out about it a couple of weeks ago.

Thx DosFreak, I'll give it a try.

I don't mind at all using Dosbox, it's just that it doesn't seem to work:

Tanks game with dosbox issue

I tested EMS Magic.

Now I have the following error message: 'not enough conventional memory. Needs 526 K'.

The EMS magic doc says that if it can't find room for a 64k contiguous space in the upper memory (or whatever its name), it will use conventional memory.
That may be why I have such an error message, enit ?

How much conventional memory do you have after running EMS magic? Type in "mem" after running it.

That is the strange thing: it says (approximate translation cuz it's in French): max size of executable program 548k.

Whereas tanks.exe needs 526k...

Do the properties of the tanks.exe file have any meaning when tanks.exe is launched from a dos windows, just afer ems magic ?

matxer wrote:

That is the strange thing: it says (approximate translation cuz it's in French): max size of executable program 548k.

Where are you getting that from? Are you telling me the size of the actual game file? If so that's no what we need.

Whereas tanks.exe needs 526k...

You need to go to Start/run/cmd.exe
Surf to the game directory.
Type in "mem".
Report the results here.

Now run EMS Magic in the same box.

Then run "mem" again.

Report the results here.

Do the properties of the tanks.exe file have any meaning when tanks.exe is launched from a dos windows, just afer ems magic ?

Unless you add EMS magic to the autoexec.nt file or you use a custom autoexec.nt file then if you launch "tanks.exe" seperate from EMS Magic then they will not have any effect on each other. Both programs must be run in the same DOS session.

See....this is why we recommend DosBox so much. (When it works which 95+% of the time it does).

Thx DosFreak, it seems the game finally wants to run under DosBox.

Thx for your help.