I wanted to try writing to video-memory directly instead of using an interrupt. Here's what I coded:

ORG 0x100

main:
mov es, [video_seg] ;Video-mem-address in es

xor di,di ;Make sure di is 0
lea si, MyString ;Load the offset of string into si
mov cx,12 ;Put the length of the string in counter-var
mov ah, 07h ; This sets black on white
cld ;Clear Direction Flag (Direction --->)

print_loop:
lodsb ;Load a byte from DS:SI into AL
stosw ;Take value from AL and save it at ES:DI
loop print_loop

RET

MyString db "Hello World!"
video_seg dw 0B800h

I get an error: Line 8: invalid combination of opcode and operands

Any help is appreciated
fabs

lea si,MyStr

could be either:

mov si,MyStr
or
lea si,[MyStr]

the second operans passed to lea should be an address, not a constant value.

oh, thx
I thought if I pass something to lea, it automatically knows I'm talking about the address but on second thought, if I had an address stored in a variable, I could wanna pass that...
Ok, so to make my proggy work, it has to be
lea dx, [MyString]
fabs

I would recommend "mov dx,MyStr", that is smaller.

ok, I did that anyway
fabs