Hello. I've been working through the tutorials on this webpage which progressively creates a bootloader that displays Hello World.

The 2nd tutorial (where we attempt to get an "A" to be output) works perfectly, and yet the 1st tutorial doesn't work for me at all! (The BIOS completely ignores the floppy disk and boots straight into Windows). This is less of an issue, although any explanations would be appreciated.

The real problem is that I can't get the 3rd tutorial to work. Instead on outputting "Hello World", I get an unusual character (and blinking cursor) in the bottom-left corner of the screen. It looks a bit like a smiley face inside a rounded rectangle. Does anyone know how to get Hello World to display as it should?