Print0xPrefix

Purpose: Emit the constant string "0x" out the COM1 console serial port.
Assumes:  Since this system call can "block", interrupts will be enabled if they are disabled when called.
Passed: Nothing.  
Returns:   Nothing.
Alters: Only R24 and the FLAGs
Example:   
.ORG  0x1000
   CALL    APrint0xPrefix        ; Print the "0x" string
   MOVW    R24, R26              ; Copy the command tail pointer to R24
   ADIW    R24, 1                ; Move it past the space
   OR      R26, R27              ; OR both Registers together, to set the ZERO
   CPSE    R26, R1               ;  flag, then if it's set, skip the call to
   CALL    APrintSRAMASCIIz      ;  print the command tail
   JMP     APrintNewLine         ; Always print Carriage Return & Line Feed
Test it: 
m>@ 0x1000
0x
m>@ 0x1000 12345
0x12345
m>@ 0x1000  Test string
0x Test string
m>
Notes: Although this is a really trivial subroutine, it was needed in quite a few places, and since it was an RCALL for most of the O.S. code, it was included.
This routine internally calls the PrintCHAR System Function (twice, actually.)
Dropin: 
(setup
code)		 
;   Setup for the Print0xPrefix() call:
; Passed:  Nothing.
; Returns: Nothing.
; Alters:  R24 and the FLAGs
Also see:  The Print0xHexBYTE, Print0xHexWORD, PrintHexBYTE, and PrintHexWORD System Functions.