Ch 11: Real-Time Interrupts & Timer Programming

Explain how BIOS Interrupt 14h Service 02h (INT 14h AH=02h) is used for serial port communication.

mov ah, 0x02
mov dx, 0
int 0x14

When utilizing BIOS Interrupt 14h serial communication services, what do the values in registers AH, AL, and DX represent?

mov ah, 0x01
mov al, 'A'
mov dx, 0
int 0x14

Which two 8-bit registers are used by BIOS INT 14h Service 02h (Read Character from Serial Port) to return output results?

mov ah, 0x02
mov dx, 0
int 0x14

Classify and list the main types of I/O peripheral devices connected to a computer system.

Fill in the missing terms regarding Serial Port UART I/O port addresses and register access: 'Serial Port is accessible via [Blank 1], where COM1 is mapped to ports [Blank 2] and COM2 is mapped to ports [Blank 3]. Port 3F8h acts as the [Blank 4] register when written to, and the receiver [Blank 5] register when read from. In register 3F9h, [Blank 6] must be set to enable received data available interrupt.'

mov dx, 0x3f8
out dx, al