What IRQ does the system timer commonly use?

What IRQ does the system timer commonly use?

• 1
• 10
• 13
• 0 

EXPLANATION

IRQ 0 - System timer. IRQ 1 - Keyboard. IRQ 2 - Cascaded signals from IRQs 8-15. IRQ 3 - COM2 (Default) and COM4 (User) serial ports
IRQ 4 - COM1 (Default) and COM3 (User) serial ports
IRQ 5 - LPT2 Parallel Port 2 or sound card
IRQ 6 - Floppy disk controller
IRQ 7 - LPT1 Parallel Port 1 or sound card (8-bit Sound Blaster and compatibles) IRQ 8 - Real time clock
IRQ 9 - Free / Open interrupt / Available / SCSI. Any devices configured to use IRQ 2 will actually be using IRQ 9.
IRQ 10 - Free
IRQ 11 - Free IRQ 12 - PS/2 connector Mouse. IRQ 13 - ISA / Math Co-Processor
IRQ 14 - Primary IDE. If no Primary IDE this can be changed
IRQ 15 - Secondary IDE These are just a set of standard IRQs. For much more detail check our Ralf Brown's list located at http://www.cs.cmu.edu/~ralf/files.html