GetDOSVectors

include vmm.inc

VMMCall GetDOSVectors

mov     [Int23], eax  ; V86 address of original Int 23 handler
mov     [Int24], edx  ; V86 address of original Int 24 handler
 

Returns the Interrupt 23h and Interrupt 24h vectors originally set by MS-DOS for the Windows virtual machine manager (VMM). This service is valid only during initialization. Uses EAX, EDX.

• Returns the Interrupt 23h vector in the EAX register and the Interrupt 24h vector in the EDX register. Each register contains a V86-mode address, with the segment in the high-order word, and the offset in the low-order word.

Virtual devices must not use this service; this service is reserved for exclusive use by the virtual MS-DOS manager.

When Windows starts, the VMM changes the original Interrupt 23h and 24h vectors to the addresses of its own handlers. When a virtual machine starts, the virtual MS-DOS manager resets these vectors to the original handlers using this service to retrieve the original addresses.

See Also

Get_PSP_Segment