Some BIOSs initialize the VGA card by default into a mode where the high
bit of background nybble signals that the cell should blink. The simple
way to avoid this is by restricting the background colours to the range
0…7. However, since our mouse cursor is implemented by swapping the
foreground and the background colours, we also need to restrict the
foreground colours to the range 0…7.
Juhani Krekelä
shikhin