;Library Name: ARRAYLIB
;Module Name: DOBLOCK
;Author: Al Hawley
;Date: 31 Mar 1987
;Version number: 1.0c

;Version History:
	
;Program Function: ARRAYLIB is a collection of subroutines which
;	implement the management of byte arrays in programs written
;	for Z80 or HD64180 based computers. This module is one of the
;	set, and may require the presence of others.

;***************************************************
;		COPYRIGHT NOTICE
;ARRAYLIB is copyright by A. E. Hawley on March 4, 1987.
;It may be freely distributed, but it must not be sold 
;either separately or as part of a package without the 
;written consent of the author.  The author may be reached 
;via electronic mail at the Ladera Z-Node in Los Angeles,
;213-670-9465, or by Voice Phone at: 213-649-3575
;
;***************************************************

	MACLIB	ARRHDR

	name doblock
;This module contains the following routines:
	public ardoblok
;..and uses the following external routines:
	ext arrc1$c2

ardoblok:
;visit a rectangular block of array elements
;performing a function that has been defined by
;a call to arvisiti:
;on entry,
;	b	= first row in block
;	c	= first column in block
;	d	= last row in block
;	e	= last column in block
;on exit,
;registers preserved: c, de
;normal return: carry flag = nc, a=0

;test needed to make sure end addr >= start addr
blockl:	push	bc
	push	de
	call	arrc1$c2	;do a row segment
;if cy set, an error code is in A.
	pop	de
	pop	bc
	ret	c		;ret if error reported by arrc1$c2
	inc	b		;next row
	ld	a,d
	cp	b		;see if b is >d
	jr	nc,blockl
	xor	a		;return no error (nc)
	ret

;**********************************************

	end