my old computer?

Look here for another list with possible solutions and workarounds:
http://www.pchell.com/hardware/beepcodes.shtml

If it's the keyboard controler, then just changing the keyboard could do. It's the first step in correcting that isue. You can have a decent plain vanila keyboard for arounf $10 for a PS2 model.

You probably have at least 2 USB ports. All computers made since 1998 have USB ports. Using any USB keyboard will bypass the motherboard's keyboard controller.

Electro
March 2013

This link...
http://www.techspot.com/community/topics/the-complete-bios-beep-guide.95391/

Suggests that a Keyboard controller has failed but that may only be for some machines - yours may be different. - Preliminary and rudimentary tests from the BIOS chip before attempting to load the Operating System.

Use Google and search for Dell ??? 6 beeps where ??? is your specific machine.

If it does come down to a new machine a Low Specification Laptop can be yours for about £300 - there is no need to pay more - there is no need for super fast performance or big disk and massive memory.

Good luck...

Peccavi
March 2013