;-------------------------scale routine begins--------------------------+
; from BLUEBOOK OF ASSEMBLY ROUTINES FOR IBM PC & XT.
;         page :173
; NAME SCALE
; ROUTINE FOR LINEAR SCALING
;
; FUNCTION: This routine performs a linear scaling, converting a fixed
; point number between 0 and 1 to an integer between X1 and X2, where
; X1 and X2 are 16-bit integers.
; INPUT: Upon entry CX has a binary fixed point number between 0 and
; 1.  The binary point is to the left of the leftmost bit.  X1 and X2 are
; variables stored in memory.
; OUTPUT: Upon exit CX contains the 16-bit integer result.
; REGISTERS USED:  Only CX is modified.
; SEGMENTS REFERENCED:  The data segment must contain the variables X1
; and X2.
; ROUTINES CALLED:  None
; SPECIAL NOTES: None
;
; ROUTINE TO SCALE LINEARLY
;
scale	proc	far
;
	push	dx		; save registers
	push	ax
;
; compute width
	mov	ax,x2		; get x2
	sub	ax,x1		; subtract x1
;
; multiply width by input parameter
	mul	cx		; multiply
	mov	cx,dx		; move top part of quotient into CX
;
; add lower limit
	add	cx,x1		; add x1
;
	pop	dx		; restore registers
	pop	dx
	ret			; return
;
scale	endp
;-------------------------scale routine ends---------------------------+