[syslinux] keyboard input under a vm

[Alexander Heinz]

> Is there any reason why the keyboard poll routine (int 16h) in conio.inc checks fro a serial port.
> 
> when pxelinux.0 is run under a vm - the keyboard does not register.
> which makes menus useless.

Murali's menu program works for me using VMWARE 4.5.1 build 7568 but if 
I exit the menu program using the left arrow key I cannot enter 
anything. The keyboard just does not work at the pxelinux prompt.