;	CP/M 2.0 disk re-definition library
;
;	Copyright (c) 1979
;	Digital Research
;	Box 579
;	Pacific Grove, CA
;	93950
;
;	Modified by:
;	Copyright (c) 1980
;	Robert M. White
;	H & W Computer Systems, Inc.
;	8530 Stonehaven
;	Boise, Idaho
;	83704
;
;
;	This set of macros provide necessary table
;	definitions for the use of the new BIOS
;	routines.
;
;
;		* * *  Disk Parameter Block  * * *
;	each parameter-list-i takes the form
;		dfc,ssc,nsc,bls,dks,dir,cks,ofs,xlt,[0]
;	where
;	dfc	is the Disk Format Code defined by DFOCO
;	ssc	is the physical host sector size 
;			(128,256,512,1024)
»	nsã	ió thå number of physical sectors per track
;	bls	is the data block size (1024,2048,...,16384)
;	dks	is the disk size in bls increments (word)
;	dir	is the number of directory elements (word)
;	cks	is the number of dir elements to checksum
;	ofs	is the number of tracks to skip (word)
;	xlt	is the optional Sector Translation Table adr
;			(should be 0 if none)
;	[0]	is an optional 0 which forces 16K/directory entry
;
ddb	macro	data,comment
;;	define a db statement
	db	data		comment
	endm
;
ddw	macro	data,comment
;;	define a dw statement
	dw	data		comment
	endm
;
;
DPB	macro	dfc,ssc,nsc,bls,dks,dir,cks,ofs,xlt,k16
;;	generate the block shift value
blkval	set	bls/128	;;number of sectors/block
blkshf	set	0	;;counts right 0's in blkval
blkmsk	set	0	;;fills with 1's from right
	rept	16	;;once for each bit position
	if	blkval=1
	exitm
	endif
;;	otherwise, high order 1 not found yet
blkshf	set	blkshf+1
blkmsk	set	(blkmsk shl 1) or 1
blkval	set	blkval/2
	endm
;;	generate the extent mask byte
blkval	set	bls/1024	;;number of kilobytes/block
extmsk	set	0	;;fill from right with 1's
	rept	16
	if	blkval=1
	exitm
	endif
;;	otherwise more to shift
extmsk	set	(extmsk shl 1) or 1
blkval	set	blkval/2
	endm
;;	may be double byte allocation
	if	(dks) > 256
extmsk	set	(extmsk shr 1)
	endif
;;	may be optional [0] in last position
	if	not nul k16
extmsk	set	k16
	endif
;;	now generate directory reservation bit vector
dirrem	set	dir	;;# remaining to process
dirbks	set	bls/32	;;number of entries per block
dirblk	set	0	;;fill with 1's on each loop
	rept	16
	if	dirrem=0
	exitm
	endif
;;	not complete, iterate once again
;;	shift right and add 1 high order bit
dirblk	set	(dirblk shr 1) or 8000h
	if	dirrem > dirbks
dirrem	set	dirrem-dirbks
	else
dirrem	set	0
	endif
	endm
;;
hstblk	set	ssc/128	;;number of CP/M sectors
;;			;; 	in a host sector
cpmspt	set	hstblk*nsc
			;;number of CP/M sectors
;;			;;	per track
secmsk	set	hstblk-1 ;;host sector mask
secrem	set	hstblk
secshf	set	0
	rept	8
	if	secrem=1
	exitm
	endif
;;	not complete, iterate once again
;;	shift right one position.
secrem	set	(secrem shr 1)
secshf	set	secshf+1
	endm
;;
;;
;;		generate the DPB.
	ddw	%cpmspt,<;# of CP/M sec/trk>
	ddb	%blkshf,<;block shift>
	ddb	%blkmsk,<;block mask>
	ddb	%extmsk,<;extnt mask>
	ddw	%(dks)-1,<;disk size-1>
	ddw	%(dir)-1,<;directory max>
	ddb	%dirblk shr 8,<;alloc0>
	ddb	%dirblk and 0ffh,<;alloc1>
	ddw	%(cks)/4,<;check size>
	ddw	%ofs,<;offset>
	ddb	%dfc,<;Disk Format Code>
	ddw	%ssc,<;host sector size>
	ddb	%secmsk,<;host sector mask>
	ddb	%secshf,<;host sector shift value>
	ddw	%xlt,<;Sector Xlat Table>
	endm
;
;
;		* * * Register Address w/disp * * *
rxad	macro	base,disp
	if	not nul base
	lhld	base		;get base address.
	endif
	if	not nul disp
	push	d		;add in disp.
	lxi	d,disp
	dad	d
	pop	d
	endif
	endm
;
;
;		* * *  Load Register w/disp  * * *
rxld	macro	reg,base,disp
	rxad	base,disp
	mov	reg,m		;get the value.
	endm
;
;
;		* * *  Load Double Register w/disp  * * *
rxdld	macro	regpr,base,disp
	rxad	base,disp
	mov	regpr+1,m	;get low byte.
	inx	h
	mov	regpr,m		;get high byte.
	endm