With the integrated BIOS debugger, bringing up and testing new hardware is straightforward, without guesswork. The debugger supports 16 and 32-bit registers, chipset and Super I/O registers, the entire 4.2GB address space, a full disassembler, and special features for controlling hardware like the cache and A20 gate.
The Debugger provides a simple human interface similar to DOS DEBUG, but built-into the BIOS itself. The engineer can get control through a special key-chord (CTL-SHF) at any time the target is running, including during POST and while DOS is executing. Entry is also possible via Setup, or from an application program with INT 3 instructions.
The debugging keyboard and screen can be redirected to a COM port where there is no keyboard or screen in the traditional sense, or in order to avoid interference with the application program.
