A2osX/ProDOS.203/ProDOS.S.XDOS.F.txt

NEW
  AUTO 3,1

destroy			jsr findfile			look for file to be destroyed.
				bcs L4B66			  	if error.
				jsr tstopen				is it open ?
				lda totent
				bne L4B64			  	error if open.
				stz reql			 	force proper free count in volume.
				stz reqh			 	(no disk access occurs if already
				jsr tstfrblk			proper)
				bcc L4B39				no errors.
				cmp #$48			 	was error a full disk ?
				bne L4B66			  	no, report error.
L4B39  			lda d_attr			 	make sure ok to destroy file.
				and #$80
				bne L4B45			  	branch if ok to destroy.
				lda #$4E			 	access error
				jsr p8errv			 	(returns to caller)
L4B45  			lda devnum			 	last device used.
				jsr twrprot1			test for write protected hardware
				bcs L4B66			  	before going thru deallocation.
				lda d_frst			 	'detree' needs first block address
				sta firstbl
				lda d_frst+1
				sta firstbh
				lda d_stor			 	find out which storage type.
				and #$F0			 	strip off name length.
				cmp #$40			 	is it a seed, sapling or tree ?
				bcc L4B68			  	branch if it is.
				bra L4BCF			  	otherwise, test for directory destroy.
L4B64  			lda #$50				file busy error.
L4B66  			sec		 				can't be destroyed
				rts
L4B68  			sta stortyp				destroy a tree file. save storage type.
				ldx #$05
				lda #$00			 	set 'detree' input variables, must be
L4B6F  			sta stortyp,x		   	in order: deblock, dtree, dsap, dseed.
				dex
				bne L4B6F			  	loop until all zero'd.
				lda #$02			 	this avoids an extra file i/o and pre-
				sta dseed+1				vents destruction of any deleted data.
				inc delflag				don't allow detree to zero index blocks.
				jsr detree				make trees and saplings into seeds.
				dec delflag				reset flag.
				bcs L4B93			  	(de-evolution)
L4B85  			ldx firstbh
				lda firstbl				now deallocate seed.
				jsr dealloc
				bcs L4B93
				jsr upbmap
L4B93  			pha		 				save possible error code.
				lda #$00			 	update directory to free entry space.
				sta d_stor
				cmp h_fcnt			 	file entry wrap ?
				bne L4BA1			 	branch if no carry adjustment.
				dec h_fcnt+1			take carry from hi byte of file entries.
L4BA1  			dec h_fcnt				mark header with one less file.
				jsr dvcbrev				go update block count in vcb (ignore
				jsr drevise				error, if any) and update dir last.
				tax		 				save possible new error code,
				pla		 				restore possible old error code.
				bcc L4BAF			  	branch if last call succeeded.
				txa		 				last call failed, use it's error code.
L4BAF  			cmp #$01			 	adjust carry accordingly
				rts
dvcbrev			ldy vcbptr			 	update block free count in vcb. point to vcb of correct device.
				lda deblock				get # of blocks recently freed.
				adc vcbbuf+20,y
				sta vcbbuf+20,y			update current free block count.
				lda deblock+1
				adc vcbbuf+21,y
				sta vcbbuf+21,y
				lda #$00			 	force re-scan from 1st bitmap
				sta vcbbuf+28,y
				rts
L4BCD  			bcc L4B85			  	branch widened (always taken)
L4BCF  			cmp #$D0			 	is this a directory file ?
				bne L4C1B			  	no, file incompatible.
				jsr fndbmap				make sure a buffer available for bitmap
				bcs L4C1A			  	if error.
				lda d_frst			 	read 1st block of directory into gbuf
				sta bloknml
				lda d_frst+1
				sta bloknml+1
				jsr rdgbuf
				bcs L4C1A
				lda gbuf+37				do any files exist in this directory ?
				bne L4BF1			  	if so, access error.
				lda gbuf+38
				beq L4BF6
L4BF1  			lda #$4E			 	access error.
				jsr p8errv			 	P8 error vector
L4BF6  			sta gbuf+4			 	make it an invalid subdirectory
				jsr wrtgbuf
				bcs L4C1A
L4BFE  			lda gbuf+2			 	get forward link.
				cmp #$01			 	test for null block into carry.
				ldx gbuf+3				get the rest of the block address.
				bne L4C0A			  	branch if not null.
				bcc L4BCD			  	was the low part null as well ?
L4C0A  			jsr dealloc				free this block.
				bcs L4C1A
				lda gbuf+2
				ldx gbuf+3
				jsr rdblk
				bcc L4BFE			  	loop until all freed
L4C1A  			rts
L4C1B  			lda #$4A			 	file incompatible
				jsr p8errv				(returns to caller)

fcbused			pha		 				mark fcb as dirty so the directory will be flushed on 'flush'.
				tya		 				save regs.
				pha
				ldy fcbptr
				lda fcbbuf+28,y			fetch current fcb dirty byte.
				ora #$80			 	mark fcb as dirty.
				sta fcbbuf+28,y			save it back
				pla		 				and restore regs.
				tay
				pla
				rts

* 'detree' deallocates blocks from tree files. it is assumed that the device has
* been pre-selected and the 'gbuf' may be used.
*
* on entry:
*  stortype = storage type in upper nibble, lower nibble is undisturbed.
*  firstbl & firstbh = first block of file (index or data).
*  deblock = 0
*  dtree = ptr to 1st block with data to be deallocated at tree level.
*  dsap = ptr to 1st block at sapling level.
*  dseed = byte (0-511) position to be zeroed from (inclusive).
*
* on exit:
*  stortype = modified result of storage type (if applicable).
*  firstbl & h = modified if storage type changed.
*  deblock = total number of blocks freed at all levels.
*  dtree, dsap, deseed unchanged.
*
* to trim a tree to a seed file, both dtree and dsap must be zero.
* to go from tree to sapling, dtree alone must be zero.

detree			lda stortyp				which kind of tree ?
				cmp #$20			 	is it a 'seed' ?
				bcc L4C46			  	if yes.
				cmp #$30			 	a sapling ?
				bcc L4C51			  	if yes.
				cmp #$40			 	is it at least a 'tree' ?
				bcc L4C59			  	branch if it is.
				lda #$0C			 	block allocation error.
				jsr sysdeath			P8 system death vector

* seedling file type - make sure first desireable block is the only
* block available in a seedling file.

L4C46  			lda dsap
				ora dtree
				bne L4CC2	
				jmp seedel0

* sapling file type - make sure first desireable block is within the range of
* blocks available in a sapling file

L4C51  			lda dtree				can't have any blocks in this range
				bne L4CC2			  	if so then done
				jmp sapdel0				else go deallocate
L4C59			lda #$80
				sta topdest				for tree top start at end, work backwards.
L4C5E  			jsr drdfrst				read specified first block into gbuf.
				bcs L4CC2			  	return errors.
				ldy topdest				get current pointer to top indexes.
				cpy dtree			  	have enough sapling indexes been
				beq L4CC3			  	deallocated? yes, now deallocate blocks
				ldx #$07				buffer up to 8 sapling index block
L4C6D  			lda gbuf,y				addresses. fetch low block address
				sta dealbufl,x			and save it.
				ora gbuf+$100,y			is it a real block that is allocated?
				beq L4C81			  	branch if phantom block.
				lda gbuf+$100,y			fetch high block address
				sta dealbufh,x			and save it.
				dex		 				decrement and test for dealc buf filled.
				bmi L4C93				branch if 8 addresses fetched.
L4C81  			dey		 				look for end of deallocation limit.
				cpy dtree			  	is this the last position on tree level?
				bne L4C6D			  	if not.
				iny
				lda #$00			 	fill rest of dealc buffer with null addresses.
L4C8A  			sta dealbufl,x
				sta dealbufh,x
				dex
				bpl L4C8A
L4C93  			dey		 				decrement to prepare for next time.
				sty topdest				save index.
				ldx #$07
L4C99  			stx dtmpx			  	save index to dealc buf.
				lda dealbufl,x
				sta bloknml
				ora dealbufh,x			finished ?
				beq L4C5E			  	branch if done with this level.
				lda dealbufh,x			complete address with high byte,
				sta bloknml+1
				jsr rdgbuf			 	read sapling level into gbuf.
				bcs L4CC2			  	return errors.
				jsr dealblk				go free all data indexes in this block
				bcs L4CC2
				jsr wrtgbuf				write the flipped index block
				bcs L4CC2
				ldx dtmpx			  	restore index to dealc buff.
				dex		 				are there more to free?
				bpl L4C99			  	branch if so.
				bmi L4C5E			  	branch always to get up to 8 more
L4CC2  			rts		 				sapling block numbers.
L4CC3  			ldy dtree			  	deallocate all sapling blocks greater
				iny		 				than specified block.
				jsr dalblk1				(master index in gbuf)
				bcs L4CC2			  	if errors.
				jsr wrtgbuf				write updated master index back to disk.
				bcs L4CC2
				ldy dtree				figure out if tree can become sapling.
				beq L4CEB			  	branch if it can.
				lda gbuf,y			 	otherwise, continue with partial.
				sta bloknml				deallocation of last sapling index.
				ora gbuf+$100,y			is there such a sapling index block ?
				beq L4CC2			  	all done if not.
				lda gbuf+$100,y			read in sapling level to be modified.
				sta bloknml+1
				jsr rdgbuf			 	read highest sapling index into gbuf.
				bcc L4CF5
				rts
L4CEB  			jsr shrink				shrink tree to sapling
				bcs L4CC2
sapdel0			jsr drdfrst				read specified sapling level index
				bcs L4CC2			  	into gbuf. branch if error.
L4CF5  			ldy dsap				pointer to last of desirable indexes.
				iny		 				inc to 1st undesirable.
				beq L4D05			  	branch if all are desirable.
				jsr dalblk1				deallocate all indexes above specified.
				bcs L4CC2
				jsr wrtgbuf				write out the index block
				bcs L4CC2
L4D05  			ldy dsap			 	prepare to clean up last data block.
				beq L4D1F			  	branch if possibility of making a seed.
L4D0A  			lda gbuf,y			 	fetch low order data block address.
				sta bloknml
				ora gbuf+$100,y			is it a real block ?
				beq L4CC2			  	if not, then done.
				lda gbuf+$100,y
				sta bloknml+1
				jsr rdgbuf			 	go read data block into gbuf.
				bcc L4D2E			  	branch if good read
				rts		 				or return error.
L4D1F  			lda dtree			  	are both tree and sap levels zero ?
				bne L4D0A			  	if not.
				jsr shrink				reduce this sap to a seed.
				bcs L4D52			  	if error.
seedel0			jsr drdfrst				go read data block.
				bcs L4D52			  	if error.
L4D2E  			ldy dseed+1				check high byte for no deletion.
				beq L4D39			  	branch if all of 2nd page to be deleted.
				dey						if dseed > $200 then all were done.
				bne L4D52			  	branch if that is the case.
				ldy dseed			  	clear only bytes >= dseed.
L4D39  			lda #$00
L4D3B  			sta gbuf+$100,y			zero out unwanted data
				iny
				bne L4D3B
				ldy dseed+1				is that all ?
				bne L4D4F			  	yes.
				ldy dseed
L4D49  			sta gbuf,y
				iny
				bne L4D49
L4D4F  			jmp wrtgbuf				update data block to disk.
L4D52  			rts		 				return error status.
drdfrst			lda firstbl				read specified 1st block into gbuf
				ldx firstbh
				jmp rdblk			  	go read it

* beware that dealloc may bring in a new bitmap block and may destroy
* locations 46 and 47 which are used to point to the current index block.

shrink			ldx firstbh				first deallocate top index block
				txa
				pha
				lda firstbl
				pha		 				save block address of this index block.
				jsr dealloc				free it from the bitmap
				pla
				sta bloknml				set master of sapling
				pla						index block address.
				sta bloknml+1
				bcs L4D8D			  	report errors.
				lda gbuf			 	get # of new 1st block from old index.
				sta firstbl
				lda gbuf+$100
				sta firstbh
				ldy #$00
				jsr swapme				flip that one entry in old top index.
				sec		 				now change file type,
				lda stortyp				from tree to sapling,
				sbc #$10			 	or from sapling to seed.
				sta stortyp
				jsr wrtgbuf				write the (deallocated) old top index.
L4D8D  			rts		 				return error status.
dealblk			ldy #$00			 	start at beginning.
dalblk1			lda bloknml				save disk address of gbuf's data.
				pha
				lda bloknml+1
				pha
L4D96  			sty saptr			  	save current index.
				lda gbuf,y			 	get low address of block to deallocate.
				cmp #$01			 	test for null block into carry.
				ldx gbuf+$100,y			get remainder of block address.
				bne L4DA5			  	branch if not null.
				bcc L4DB0			  	was the low part null too ?
L4DA5  			jsr dealloc				free it up on volume bitmap.
				bcs L4DB4			  	return any error.
				ldy saptr			  	get index to sapling level index block.
				jsr swapme			 
L4DB0  			iny		 				next block address.
				bne L4D96			  	if more to deallocate or test.
				clc		 				no error.
L4DB4  			tax		 				save error code, if any.
				pla		 				restore blocknm (16 bit)
				sta bloknml+1
				pla
				sta bloknml
				txa		 				restore return code
				rts
swapme			lda delflag				swapping or zeroing ?
				bne L4DC5			  	skip if swapping.
				tax		 				make x = 0.
				beq L4DCB			  	zero the index (always taken).
L4DC5  			ldx gbuf+$100,y		   	index high
				lda gbuf,y			 	index low
L4DCB  			sta gbuf+$100,y		   	save index high
				txa
				sta gbuf,y			 	save index low
				rts						done.

* MEMMGR memory manager
*
* allocate buffer in memory tables

alcbuffr 		ldy #$04				index to user specified buffer.
alcbufr1 		lda (A3L),y				this buffer must be on a page boundary.
				tax		 				save for validation.
				cmp #$08
				bcc L4E1E			  	cannot be lower than video !
				cmp #$BC				nor greater than $BB00
				bcs L4E1E			  	since it would wipe out globals...
				sta datptr+1
				dey
				lda (A3L),y				low address should be zero !
				sta datptr
				bne L4E1E			  	error if not page boundary.
				inx		 				add 4 pages for 1k buffer.
				inx
				inx
				inx
L4DED			dex		 				test for conflicts.
				jsr cmembit				test for free buffer space
				and memmap,y			P8 memory bitmap
				bne L4E1E			  	report memory conflict, if any.
				cpx datptr+1			test all 4 pages.
				bne L4DED
				inx		 				add 4 pages again for allocation.
				inx
				inx
				inx
L4DFE  			dex		 				set proper bits to 1
				jsr cmembit
				ora memmap,y			to mark it's allocation.
				sta memmap,y
				cpx datptr+1			set all 4 pages
				bne L4DFE
				ldy fcbptr			 	calculate buffer number
				lda fcbbuf,y
				asl			  			buffer number = (entnum) * 2.
				sta fcbbuf+11,y			save it in fcb.
				tax		 				use entnum * 2 as index to global
				lda datptr+1			buffer addr tables. get addr already
				sta buftbl-1,x			validated as good. store hi addr
				clc		 				(entnums start at 1, not 0)
				rts
L4E1E  			lda #$56			 	buffer is in use or not legal
				sec
				rts
getbufadr 		tax						index into global buffer table.
				lda buftbl-2,x
				sta bufaddrl
				lda buftbl-1,x
				sta bufaddrh
				rts
relbuffr 		jsr getbufadr			preserve buffer address in 'bufaddr'
				tay		 				returns high buffer address in acc.
				beq L4E54			 	branch if unallocated buffer space.
				stz buftbl-1,x			take address out of buffer list.
				stz buftbl-2,x			(x was set up by getbufadr)
freebuf			ldx bufaddrh			get hi buffer address
				inx		 				add 4 pages to account for 1k space.
				inx
				inx
				inx
L4E43  			dex		 				drop to next lower page.
				jsr cmembit				get bit and position to memtable of
				eor #$FF			 	this page. invert mask.
				and memmap,y			mark address as free space.
				sta memmap,y
				cpx bufaddrh			all pages freed ?
				bne L4E43			  	no.
L4E54  			clc		 				no error.
				rts

* calculate memory allocation bit position.
* on entry: x = high address of buffer, low address assumed zero.
* on exit: acc = allocation bit mask, x = unchanged, y = pointer to memtabl byte

cmembit			txa						page address
				and #$07			 	which page in any 2k set ?
				tay		 				use as index to determine
				lda whichbit,y			bit position representation.
				pha		 				save bit position mask for now.
				txa		 				page address.
				lsr
				lsr			  			determine 2k set
				lsr
				tay		 				return it in y.
				pla		 				restore bit mask. return bit position
				rts		 				in a & y, pointer to memtabl in x.
valdbuf			lda usrbuf+1			high address of user's buffer
				cmp #$02			 	must be greater than page 2.
				bcc L4E1E			  	report bad buffer
				ldx cbytes+1
				lda cbytes			 	get cbytes-1 value.
				sbc #$01			 	(carry is set)
				bcs L4E76
				dex
L4E76  			clc
				adc usrbuf			 	calculate end of request address.
				txa		 				do high address.
				adc usrbuf+1			the final address
				tax		 				must be less than $BFnn (globals)
				cpx #$BF
				bcs L4E1E			  	report bad buffer.
				inx		 				loop thru all affected pages.
vldbuf1			dex		 				check next lower page.
				jsr cmembit
				and memmap,y			if 0 then no conflict.
				bne L4E1E			  	branch if conflict.
				cpx usrbuf+1			was that the last (lowest) page ?
				bne vldbuf1			 	if not.
				clc		 				all pages ok.
				rts

getbuf			ldy #$02			 	give user address of file buffer referenced by refnum.
				lda bufaddrl
				sta (A3L),y
				iny
				lda bufaddrh
				sta (A3L),y
				clc		 				no errors possible
				rts

setbuf			ldy #$03
				jsr alcbufr1			allocate new buffer address over old one
				bcs L4EC7				report any errors immediately
				lda bufaddrh
				sta usrbuf+1
				lda bufaddrl
				sta usrbuf
				jsr freebuf				free address space of old buffer
				ldy #$00
				ldx #$03
L4EB8  			lda (usrbuf),y			move all 4 pages of the buffer to
				sta (datptr),y			new location.
				iny
				bne L4EB8
				inc datptr+1
				inc usrbuf+1
				dex
				bpl L4EB8
				clc		 				no errors
L4EC7  			rts


* move 3 pages of dispatcher from 'displc2' to 'dispadr'
* this move routine must be resident above $E000 at all times

calldisp 		lda RRAMWRAMBNK2		read/write RAM bank 2
				lda RRAMWRAMBNK2
				lda /dispadr
				sta A2L+1
				lda #dispadr
				sta A2L
				lda /displc2
				sta A1L+1
				stz A1L
				ldy #$00
				ldx #$03				3 pages to move.
L4EE0  			dey		 				move a page of code.
				lda (A1L),y
				sta (A2L),y
				tya
				bne L4EE0
				inc	A1L+1			  	pointers to next page
				inc	A2L+1
				dex		 				move all pages needed
				bne L4EE0
				lda RRAMWRAMBNK1		read/write RAM bank 1
				lda RRAMWRAMBNK1		swap mli space back in
				stz mliact			 	MLI active flag
				stz softev			 
				lda /dispadr			point RESET to dispatch entry
				sta softev+1
				eor #$A5
				sta pwredup				power up byte
				jmp dispadr

* translate a prodos call into a smartport call
* to access unseen smartport devices

remap_sp 		ldx #$03				assume 3 parameters.
				lda A4L			  		command number
				sta cmdnum
				bne L4F1B				taken if not status call
				ldy #spstatlist			set up memory for the status list buffer
				sty buf					fake up the prodos parameters
				ldy /spstatlist
				sty buf+1
				stz bloknml				set statcode = 0 for simple status call
L4F1B  			cmp #$03			 	format command ?
				bne L4F21			  	no.
				ldx #$01			 	format has only 1 parameter.
L4F21  			stx statparms			set # of parms.
				lda unitnum			
				lsr			  			turn unit number into an index
				lsr
				lsr
				lsr
				tax
				lda spunit-1,x			get the smartport unit number and
				sta sp_unitnum			store into smartport parm list.
				lda spvectlo-1,x	
				sta sp_vector+1			copy smartport entry address
				lda spvecthi-1,x
				sta sp_vector+2
				ldx #$04				copy buffer pointer and block #
L4F3F  			lda buf-1,x				from prodos parameters
				sta sp_bufptr-1,x		to smartport parameter block
				dex
				bne L4F3F
				
sp_vector 		jsr $0000				smartport call (entry address gets modified)
cmdnum			.HS 00					command #
				.DA statparms
				bcs	L4F6E
				ldx cmdnum				status call ?
				bne L4F6E			  	no...
				ldx spstatlist+1		else get the block count
				ldy spstatlist+2
				lda	spstatlist			get the returned status.
				bit #$10			 	is there a disk present ?
				bne L4F65			  	yes, check for write protected.
				lda #$2F			 	return offline error.
				bra L4F6D
L4F65  			and #$44			 	mask all but write allowed and write
				eor #$40			 	protected bits. if allowed and not
				beq L4F6E			  	protected, exit with carry clear
				lda #$2B			 	else return write protected error.
L4F6D  			sec
L4F6E  			rts
spvectlo 		.HS 0000000000000000  	storage for low byte of smartport entry.
				.HS 00000000000000
spvecthi 		.HS 0000000000000000  	storage for high byte of smartport entry.
				.HS 00000000000000
statparms 		.HS 03					# of parms (always 3 except format)
sp_unitnum 		.HS 00			  		unit number
sp_bufptr 		.HS 0000				data buffer
				.HS 000000				block number (3 bytes)

* data tables

scnums			.HS D3000000			table of valid mli command numbers.
				.HS 40410000808182
				.HS 65C0C1C2C3C4C5C6
				.HS C7C8C9CACBCCCDCE
				.HS CF00D0D1D2
				
pcntbl			.HS 02FFFF				parameter counts for the calls
				.HS FF0201FFFF030300
				.HS 04070102070A0201
				.HS 0103030404010102
				.HS 02FF020202

* command table

cmdtable 		.DA create
				.DA destroy
				.DA rename
				.DA setinfo
				.DA getinfo
				.DA online
				.DA setprefx
				.DA getprefx
				.DA openf
				.DA newline
				.DA readf
				.DA writef
				.DA closef
				.DA flushf
				.DA setmark
				.DA getmark
				.DA seteof
				.DA geteof
				.DA setbuf
				.DA getbuf

* corresponding command function bytes

disptch			.HS A0A1A2A3
				.HS 84050607
				.HS 88494A4B
				.HS 2C2D4E4F
				.HS 50515253

dinctbl			.HS 0100000200			table to increment directory usage/eof counts
pass			.HS 75
xdosver			.HS 00
compat			.HS 00
				.HS C3270D000000
rootstuf 		.HS 0F02000400000800
whichbit 		.HS 8040201008040201
ofcbtbl			.HS 0C0D1819151617
inftabl			.HS 1E101F2080939421
				.HS 22232418191A1B
deathmsg 		.HS 20
				.AS -"RESTART SYSTEM-$01"
				.HS 20

*** work space ***

* note: this area is accessed by code that depends on the order of these
*   variables in the file control block and temporary directory.

own_blk			.HS 0000
own_ent			.HS 00
own_len			.HS 00
h_credt			.HS 0000				directory creation date
				.HS 0000				directory creation time
				.HS 00			 	 	version under which this dir created
				.HS 00			 	 	earliest version that it's compatible
h_attr			.HS 00				 	attributes (protect bit, etc.)
h_entln			.HS 00				 	length of each entry in this directory
h_maxent 		.HS 00				 	maximum number of entries per block
h_fcnt			.HS 0000			 	current # of files in this directory
h_bmap			.HS 0000			 	address of first allocation bitmap
h_tblk			.HS 0000			 	total number of blocks on this unit
d_dev			.HS 00				 	device number of this directory entry
d_head			.HS 0000			 	address of <sub> directory header
d_entblk 		.HS 0000				address of block which contains entry
d_entnum 		.HS 00				 	entry number within block
d_stor			.HS 0000000000000000  	file name
				.HS 0000000000000000
d_filid			 .HS 00				 	user's identification byte
d_frst			.HS 0000			 	first block of file
d_usage			.HS 0000			 	# of blocks allocated to this file
d_eof			.HS 000000			 	current end of file marker
d_credt			.HS 0000				file creation date
				.HS 0000				file creation time
d_sosver 		.HS 00					sos version that created this file
d_comp			.HS 00				 	backward version compatibility
d_attr			.HS 00				 	attributes (protect, r/w, enable, etc.)
d_auxid			.HS 0000			 	user auxilliary identification
d_moddt			.HS 0000				file's last modification date
				.HS 0000				file's last modification time
d_dhdr			.HS 0000			 	file directory header block address
scrtch			.HS 00000000			scratch area for allocation address conversion.
oldeof			.HS 000000				temp used in r/w
oldmark			.HS 000000
xvcbptr			.HS 00				 	used in 'cmpvcb' as a temp
vcbptr			.HS 00
fcbptr			.HS 00
fcbflg			.HS 00
reql			.HS 00			  
reqh			.HS 00
levels			.HS 00
totent			.HS 00
entcntl			.HS 00
entcnth			.HS 00
cntent			.HS 00
nofree			.HS 00
bmcnt			.HS 00			  
saptr			.HS 00
pathcnt			.HS 00
p_dev			.HS 00
p_blok			.HS 0000
bmptr			.HS 00
basval			.HS 00
half			.HS 00

* bitmap info tables

bmastat			.HS 00
bmadev			.HS 00
bmadadr			.HS 0000
bmacmap			.HS 00
tposll			.HS 00
tposlh			.HS 00
tposhi			.HS 00
rwreql			.HS 00
rwreqh			.HS 00
nlchar			.HS 00
nlmask			.HS 00
ioaccess 		.HS 00			 		has a call been made to disk device handler ?
cmdtemp			.HS 00
bkbitflg		.HS 00					used to set or clear backup bit
duplflag 		.HS 00
vcbentry 		.HS 00

* xdos temporary variables

namcnt			.HS 00
rnptr			.HS 00
namptr			.HS 00
vnptr			.HS 00
prfxflg			.HS 00
cferr			.HS 00

* deallocation temporary variables

firstbl			.HS 00
firstbh			.HS 00
stortyp			.HS 00
deblock			.HS 0000
dtree			.HS 00
dsap			.HS 00
dseed			.HS 0000
topdest			.HS 00
dtmpx			.HS 00
loklst			.EQ	*					look list of recognized device numbers
dealbufl 		.HS 0000000000000000
dealbufh 		.HS 0000000000000000
cbytes			.HS 0000
				.HS 00					cbytes+2 must = 0
bufaddrl		.HS 00			  
bufaddrh 		.HS 00
goadr			.HS 0000
delflag			.HS 00			  		used by 'detree' to know if called from delete (destroy).

* zero fill to page boundary - 3 ($FEFD). so that cortland flag stays
* within page boundary.

				.HS 00000000000000
				.HS 0000000000
					
				.DA calldisp
cortflag 		.HS 00			  		cortland flag. 1 = Cortland system (must stay within page boundary)
*--------------------------------------
MAN
SAVE USR/SRC/PRODOS.203/PRODOS.S.XDOS.F
LOAD USR/SRC/PRODOS.203/PRODOS.S
ASM