Arthur: It's a LIFO (Last In First Out) buffer that goes backwards. It should go back to 0000h and then the app will reset SS:SP to (next segment):FFFFh.
Oh, and BTW, if you don't have the right patch:
1. Open MS-DOS Prompt. (It's patched in 98SE and 98 with Y2K bugfix)
2. Type in cd \windows\command. If you aren't in C: drive, type in c: first.
3. Now type in edit con.bat.
4. Type in echo hello, go to File->Save, and type in con.bat as a file name.
5. Save it, and watch your computer crash like it has never crashed before.
NB: Sometimes this crashes your PC badly. Other times it just gives you a standard Windows crash message.
Now, someone come back to HOME-MADE PROGRAMS...