I have a Dell keyboard that was working fine. I then sent some scan
code down to it - I cannot remember the exact scan code that I used
(certainly an 0xAA and 0x AB). But is was based on this :-

http://www.win.tue.nl/~aeb/linux/kbd...s-9.html#ss9.1

8.3 Keyboard controller commands
The CPU can command the keyboard controller by writing port 0x64.
Useful, generally available, keyboard commands a

20 Read keyboard controller command byte
60 Write keyboard controller command byte
aa Self test
ab Interface test
ad Disable keyboard
ae Enable keyboard
c0 Read input port
d0 Read output port
d1 Write output port
e0 Read test inputs
fe System reset

Is there any way for me to repair or recover the keyboard?

Thanks,
John