You might try using the LOADFIX utility that is built into DOSBox. For example, if you run the game by typing SIERRA, you would type:
LOADFIX SIERRA

Also, make sure that you've run INSTALL and that you've chosen valid options for video and sound.

That's weird. I did that, but now it won't enter the game because it "can't install video drivers".

Are you sure you ran the INSTALL utility and selected valid settings? What does your resource.cfg look like?

Figured out what was wrong with that (nothing in the resource.cfg), and fixed it. Unfortunately, loadfix doesn't fix anything. Still gives "out of heap space"

Hmm... This page suggests that maybe running at a slower speed (lower cycles setting) will help: http://www.the-underdogs.org/tech/techelp_p.h … fheapspaceerror

OK...how do I run Moslo under Dosbox?

There's no reason to. Just set the cycles setting lower in DOSBox and it will run slower.

Tried that. Tried it at 100 cycles (with turbo set to 1%) before I quit.

Went into a game that tells the exact number of XMS memory (STTNG:AFU) and it said there was a grand total of -2112. No wonder my game's out of heap.

Conquests of Camelot doesn't use XMS memory. Also, the "heap" size depends on the program. For a program that only uses regular DOS memory, this won't be bigger than 640k (less, actually, since the program itself also takes up memory, as does DOS etc).

For a program that runs in protected mode, the heap could be the size of the physical memory in the system or even more (if a page file exists). STTNG:AFU runs in protected mode. It giving you a negative amount of memory simply means that it's experiencing integer overflow. From the looks of it, you've set your DOSBox to have around 64MB of memory.

This strange number is not the cause of the problem with CoC.