INT 15 - MultiDOS Plus 4.01 - SET CONTEXT-SWITCH FUNCTIONS                      
	AX = 1E08h
	DX:BX -> context save handler (see #00458)
	DX:CX -> context restore handler (see #00458)
Return: nothing
Note:	handlers may be removed by setting addresses to 0000h:0000h


(Table 00458)
Values MultiDOS Plus context-switch handlers are called with:
	ES:BX -> task's TCB
Return: all registers preserved