Hi there, just receantly discovered your emulator and thought I'd drop a suggestion for a resource that might help you in improving it. Please forgive me if you ahve this or if it's been suggested before, I ran a couple searches on the boards and couldn't find anything.

Playing with your emulator made me think of an old reference book I used to have, and still do have that was the most complete reference of DOS I've ever seen. It starts with about 450 pages covering the complete structure of DOS with lots of programming examples. Probably nothing you don't know, but worth a look. The real meat is the 600 odd pages of interrupt documentation. I contains a complete record of all the hardware, BIOS, DOS, EMS, XMS, and DPMI interrupts, all subfunction and precisely what they do, including undocumented ones.

The book is called DOS Programmer's Reference, 4th edition. It's from Que, written by Terry Dettmann. You can find it on Amazon for about $12.

If you don't have it, you really should check it out. I think you'll find it really helpful for the arcane aspects of some of this stuff. At the very least, it's a nicely compiled reference.