Routine:        Intfp   
Function:       Converts a two byte positive integer to floating point format.
Called by:      Pc, Range.
Calls:          None
Entry:          HL holds the integer, IX points to the Floating point variable.
Exit:           FP stored at IX
Preserved:      None


INTFP   XOR     A
        OR      H
        OR      L
        JR      NZ,INTFP1
; If the number to be converted is zero, enter the floating point zero, defined as 0,0,0,0,128, and return.
        LD      B,128
        JR      INTFP3
INTFP1  LD      B,16
; Rotate the integer, decreasing the exponent, until the leftmost bit is a 1.
INTFP2  BIT     7,H
        JR      NZ,INTFP3
        ADD     HL,HL
        DEC     B
        JR      INTFP2
INTFP3  RES     7,H
        LD      (IX+4),B
        LD      (IX+3),H
        LD      (IX+2),L
        XOR     A
        LD      (IX+1),A
        LD      (IX+0),A
; Store the floating point number at the specified location.
        RET