How does an OS communicate with other hardware components?
- by Jack
How can a program running on a CPU (mostly OS) access other PC hardware? Such as Graphic card, HDD and so?
From what I read, in DOS, this was done using BIOS calls, specifically the INT instruction. But, the INT instruction should only jump to the certain space in RAM. So how can some program stored in RAM access other computer hardware, when the CPU can only access RAM, and receive interrupts?
Does Windows use INT instructions as well, or is there a new way to communicate with the hardware?