EBX: Contains the Windows VM Handle.
EBP: Contains the Windows VM's Client Registers.
Save anything that you use.
The Main VDD requests that the mini-VDD restore the previous bank so that the Windows display driver will draw in the correct place on the screen. The previous bank should have been saved off by SET_VDD_BANK. Before resetting the bank, make sure that the bank that is currently set into the hardware is still the VDD bank determined when GET_VDD_BANK was called. If it is not, you must not reset the bank since a program (such as the Windows display driver) may have set it to another value without notifying the VDD.