;	EXLPAT.ASM - Fix initialization problem with output fcb in EXL.COM
;
;	Author: Mike Freeman 11-Jun-1991
;
; The author does not warrant this patch; it works for him.
; Complaints may be sent to:
; Mike Freeman
; 301 N.E. 107th Street
; Vancouver, WA 98685 USA
; Telephone (206)574-8221
; Internet: FREEMAN@WATSUN.CC.COLUMBIA.EDU
; GEnie:  M.FREEMAN11
;
; The problem: If EXL has been asked to write a file to disk and the
; extension of the output file is not 3 characters in length, the last
; character is set to <null> (yes, that's right, a binary zero) so that the
; file cannot be accessed by CP/M or other utilities until it is renamed via
; NSWEEP, RENAMZ or some such. This file contains a patch to EXL which
; fixes the problem.
; Patch rationale:  If EXL has been asked to write a file to disk, the
; output FCB is first initialized before the name of the output file is
; copied into it. This is done with a sequence like:
;	ld	hl,<address>
;	ld	de,<address+1>
;	ld	bc,<length>
;	ld	(hl),<value>
;	ldir
; which works fine. This is first done to init the filename/filetype to
; blanks (20H). The register HL is left pointing to the last position
; in the filetype, now initialized to a blank. EXL's author wishes to
; init the rest of the FCB to zero. Ideally, he/she (no name is given in
; EXL's documentation) should do the following:
;	inc	hl
;	inc	de
;	ld	bc,20
;	ld	(hl),0
;	ldir
; to init the rest of the FCB to 0. However, HL and DE are not incremented
; so that when the ldir is done, the last position in the filetype is zeroed
; and the last position in the FCB is not guaranteed to be 0. This is fixed
; by putting 12 spaces (the first directly and the rest by ldir) into the
; output FCB, thus guaranteeing that HL and DE are properly incremented
; before the rest of the FCB is zeroed. This does no harm since the direct
; zeroing of the byte pointed to by HL, via the author's
;	ld	(hl),b		;BC is 20 so B=0
; will overwrite the extra space we added with the first ldir.
; The fix is to copy 11 bytes (each a space) rather than 10 as in the
; original EXL.COM.
; Now to the fix:
;
	ORG	0653H		;Position to overlay EXL properly
;
	LXI	B,11		;Have the ldir copy 11 bytes
;
; That's all, folks!