(Part 4)
Interrupts
Interrupts can be seen as a number of functions. These functions
make the programming much easier, instead of writing a code to print a
character you can simply call the interrupt and it will do everything for
you. There are also interrupt functions that work with disk drive and other
hardware. We call such functions software interrupts.
Interrupts are also triggered by different hardware, these are called
hardware interrupts. Currently we are interested in software
interrupts only.
To make a software interrupt there is an INT instruction, it has
very simple syntax:
INT value
where value can be a number between 0 to 255 (or 0 to 0FFh), generally
we will use hexadecimal numbers.