Service Function 0003h Resume Switcher

les di, NewService ;new address of service-function handler

mov ax, 0003h ;Resume Switcher

call [Service] ;Service-function handler

jc error_handler

Resume Switcher (Function 0003h) notifies a suspended task switcher that it can resume operation.

Client programs must not call this function.

Parameter

NewService

Points to the new task switcher's service-function handler. The task switcher that is being resumed can use this address to call the new task switcher's service functions, such as Get Version (Service Function 0000h).

Return Value

If the function is successful, the carry flag is clear and the AX register contains 0000h. If the task switcher does not support this function, the carry flag is set.

Comments

A task switcher that has disabled another task switcher by using Suspend Switcher (Service Function 0002h) should call Resume Switcher to reenable it, and should use the same service-function-handler address that it used to call Suspend Switcher.

A task switcher processing Resume Switcher can enable interrupts and call any MS-DOS system function. Although the task switcher modifies the AX register, it must preserve all other registers.

See Also

Service Function 0000h Get Version
Service Function 0002h Suspend Switcher