If you have unused areas in your upper memory area between CC00 and E3FF, try this for your config.sys

1DOS=HIGH,UMB
2Device=C:\dos\himem.sys
3device=C:\dos\emm386.exe RAM I=B000-B7FF I=CC00-DBFF I=DC00-DFFF I=E000-E3FF FRAME=CC00 NOTR

For FREEDOS, you can tell JEMMEX to just ENABLE the ram already mapped there as UMB.

1Device=C:\freedos\jemmex.exe RAM S=CC00-E3FF FRAME=CCOO I=TEST

The issue you are having isnt really from seabios per-se.

An actual dos machine maps NOTHING (as in, the space is conected to nothing at all, unless you assign it with jumpers on a card!) between CFFF and EFFF. This area is reserved for memory mapped IO devices, like EMS ram cards, and option roms.

Your emulator is populating this area with RAM.

This is 'basically the same thing' that UMBPCI does; find unused/unpopulated address in this area, and fill it with RAM (using the chipset).

Your emulator is giving you this 'for free'. No driver needed.

However, EMM drivers find this RAM and get mad. They expect 'NOTHING' there, find RAM, and get uppity.

EMM386 can be explicitly told to use the address *regardless of what's there* with explicit includes. (Like with my first example).

Jemmex can be told to enable this already mapped ram for umbs with the S=xxxx notation, as per the second example.

In both cases, the EMM will fail to find an area with 'NOTHING' present already to place the EMS pageframe.

However, explicitly telling the EMM where to place it, will shut it up, and it will work. The EMM just unmap the ram, then handle that 64kb chunk of address for the pageframe.

Thank you, the configuration worked! Those parameters always seemed like a lot of voodoo to me, but your explanation made it clear.

Glad it worked for you!