Function  26h  Create New Program Segment Prefix (PSP) 
     This service copies the current program-segment prefix to a new memory  
     location for the creation of a new program or overlay. Once the new PSP is 
     in place, a DOS program can read a DOS COM or overlay file into the memory  
     location immediately following the new PSP and pass control to it. 
entry   AH      26h 
	DX      segment number for the new PSP 
return  none 
note 1) Microsoft recommends you use the newer DOS service 4Bh (EXEC) instead. 
     2) The entire 100h area at location 0 in the current PSP is copied into 
	location 0 of the new PSP. The memory size information at location 6 
	in the new segment is updated and the current termination, ctrl-break, 
	and critical error addresses from interrupt vector table entries for 
	ints 22h, 23h, and 24 are saved in the new program segment starting at 
	0Ah. They are restored from this area when the program terminates. 
     3) Current PSP is copied to specified segment