He says that he can print the first character. I suppose it is possible that the direction flag is set when the boot sector gets control, so instead of pointing to the e after the H has been printed,...

I was using the syntax used by C and some assemblers.




In the case of a boot sector cs=0 and ip=7c00h (always).

Since I use MASM it recognises 7c00h, but if I used NASM it would recognise 0x7c00.

I'm not clobbering anything. The boot sector always gets loaded at an absolute address of 7c00h, which means that the ds register must contain zero if the code is org'd at 7c00h.

org 0x7c00

cli ;disable hardware interrupts
cld ;clear direction flag
xor ax,ax ...

You could try initialising the ds register with a value of zero. It might be a good idea to set up a stack as well.


cli
xor ax,ax
mov ds,ax
mov ss,ax
mov sp, 0x7c00

I tried typing it in to debug, and it worked ok for me.