RBIL61 - INT 2F - DOS 3.0+ internal - GET LENGTH OF ASCIZ STRING {undocumented}

INT 2F U - DOS 3.0+ internal - GET LENGTH OF ASCIZA NUL-terminated ASCII string.	The ASCIZ string "ABC" consists of the four bytes 41h, 42h, 43h, and 00h.  Unless otherwise specified, maximum lengths given in the interrupt list do not include the terminating NUL. STRING
	AX = 1225h
	DS:SI -> ASCIZA NUL-terminated ASCII string.	The ASCIZ string "ABC" consists of the four bytes 41h, 42h, 43h, and 00h.  Unless otherwise specified, maximum lengths given in the interrupt list do not include the terminating NUL. string
Return: CX = length of string
Note:	supported by DR DOS 5.0+
SeeAlso: AX=1212h