ASM: operand size mismatch for 'out' error

Question

I'm a beginner in ASM programming and I'm trying to read the PIT count. However the following code generates the error: "operand size mismatch for 'out'". (I'm using AT&T syntax)

movb $0b00000100, %al
outb %al, 0x43

How can I solve it? Thanks for your help!

Answer 1

The following code works:

outb %al, $0x43

Thanks.