Call With
EBX: Contains the VM handle (always the currently executing VM).
EBP: Points to the Windows VM's Client Registers.
Return Values
Save everything that you use. CY returned means that the mini-VDD handled the call. NC returned means that Main VDD should use a VESA call to retrieve the bank. If successful, EDX contains the current bank (write or read) as set in hardware.
Remarks
GET_CURRENT_BANK_WRITE and GET_CURRENT_BANK_READ are made when the user presses ALT-TAB to switch away from a VESA hi-res application. The Main VDD uses GET_CURRENT_BANK_WRITE to retrieve the current state of the banking registers (which are "Windows" in VESA terminology). It then saves these for later restoration when the user presses ALT-TAB back to the VESA hi-res application. The Main VDD uses VESA function 4F05h to get the bank if the mini-VDD fails this call.