; RS version 1.40 (c) 1986 ESKAY Software Service
;
; N O T E
;
; RS is a variant of RELED with a certain specific purpose.
; ESKAY Software Service does not support or encourage
; copyright infringements and RS should only be used
; in cases of extreme emergency, or after clearing its use
; with the copyright holder!!!!!
;
.z80
;
cr	equ	0dh
lf	equ	0ah
dfcb	equ	5ch
dbuf	equ	80h
;
; syslib externals
;
.request syslib
	extrn	print,phl4hc,phlfdc,pfn2,crlf,pstr
	extrn	bbline,condin,cout,eval10,compb
	extrn	f$open,f$read,f$write,f$close,initfcb
	extrn	codend
;
; other externals
;
	extrn	getbit		;get one bit from bit field
	extrn	putbit		;put one bit into bit field
	extrn	wildex
;
	cseg
;
begin:	ld	sp,stack
	call	print
	db	cr,lf,lf
	db	9,9,' ----------------------------------------',cr,lf
	db	9,9,'|              RS version 1.4            |',cr,lf
	db	9,9,'|               RESERIALIZER             |',cr,lf
	db	9,9,'|       USE THIS PROGRAM RESPONSIBLY     |',cr,lf
	db	9,9,'| (c) infrigement is YOUR responsibility |',cr,lf
	db	9,9,' ----------------------------------------',cr,lf,lf,0
	ld	a,(dfcb+1)
	cp	' '
	jp	z,nofile
	ld	hl,dfcb+9
	ld	(hl),'R'
	inc	hl
	ld	(hl),'E'
	inc	hl
	ld	(hl),'L'
getor:	call	print
	db	cr,lf
	db	'Enter new value for ?ORIG? in DECIMAL : ',0
	call	bbline
	or	a
	jr	z,getor
	call	eval10
	ld	(newo),de
getun:	call	print
	db	cr,lf
	db	'Enter new value for ?UNIT? in DECIMAL : ',0
	call	bbline
	or	a
	jr	z,getun
	call	eval10
	ld	(newu),de
	call	codend		;get buffer addr
	ld	(fnbuf),hl
	ld	de,1000h	;handle up to 256 files
	add	hl,de
	ld	(buffer),hl
	push	hl
	pop	ix		;ix is buffer ptr
	ld	de,dfcb
	ld	hl,(fnbuf)
	call	wildex
	jp	z,nofile
	call	print
	db	cr,lf
	db	'Matching files: ',0
	call	phlfdc
	inc	hl
	ld	(files),hl
	call	print
	db	cr,lf,lf,0
nextf:	ld	hl,(files)
	dec	hl
	ld	(files),hl
	ld	a,h
	or	l
	jp	z,finish
	xor	a
	ld	(chgd),a
	ld	(bithi),a
	ld	h,a
	ld	l,a
	ld	(bitml),hl
	ld	de,dfcb
	ld	hl,(fnbuf)
	ld	bc,16
	ldir
	ld	(fnbuf),hl
	ld	de,dfcb		;point to file name
	call	initfcb
	push	de
	inc	de
	call	print
	db	cr,lf
	db	'Now processing ',0
	call	pfn2
	pop	de
	call	f$open		;open it
	jp	nz,notfnd	;not there!
	ld	hl,(buffer)	;hl=buffer start
lodlp:	call	f$read		;read a sector
	jr	nz,allrd	;done?
	ld	bc,dbuf		;bc=buffer ptr
movlp:	ld	a,(bc)
	ld	(hl),a
	inc	hl
	inc	c
	jr	nz,movlp
	jr	lodlp
;
allrd:	call	f$close
	call	print
	db	', size ',0
	ld	(eofptr),hl
	push	hl
	ld	hl,(buffer)
	ex	de,hl
	pop	hl
	or	a
	sbc	hl,de
	call	phl4hc
	call	print
	db	'H bytes.',cr,lf,lf,0
;
; this is the main evaluation loop
; come here for every new item
;
eval:	ld	e,0
	call	get1		;get 1 bit
	or	a
	jr	nz,not8
	call	get8		;get next 8 bits (and swallow them)
	jr	eval
;
; get next 2 bits and interpret
;
not8:	call	get2
	or	a		;see if special item
	jr	z,spec
	call	get8		;swallow 16 bits
	call	get8
	jr	eval
;
; evaluate special item
;
spec:	call	get4		;get 4-bit field
;
; following items followed by name field
;
	or	a		;entry symbol
	jp	z,skipn		;skip name
	cp	1		;select common
	jp	z,skipn		;skip name
	cp	2
	jp	z,name		;display module name
	cp	3		;request item
	jp	z,skipn
;
; following items followed by value and name field
;
	cp	5		;common size
	jp	z,skpvn		;skip val/name
	cp	6		;chain external
	jp	z,skpvn		;skip it
	cp	7		;define entry point
	jp	z,ckntry	;check if we want something
;
	cp	15		;end of file?
	jp	z,eof
	cp	14		;end module
	jp	z,endm
;
; all others followed by value field
; let's swallow it
;
	call	skpval
	jr	eval
;
; end of module - skip to next byte boundary
;
endm:	ld	a,9		; a tab
	call	cout
	ld	a,(rsmod)
	or	a		; rsed this?
	ld	hl,rsedy
	jr	nz,.em..
	ld	hl,rsedn
.em..:	call	pstr
	call	crlf
	call	skpval
	ld	hl,(bitml)
	ld	de,7
	add	hl,de
	jr	nc,..em
	ld	a,(bithi)
	inc	a
	ld	(bithi),a
..em:	ld	a,l
	and	0f8h
	ld	l,a
	ld	(bitml),hl
	jp	eval
;
eof:	call	print
	db	cr,lf
	db	'end of file',cr,lf,0
	ld	a,(chgd)
	or	a
	jr	nz,wrback
	call	print
	db	'Unchanged - not saved',cr,lf,0
	jp	nextf
;
wrback:	ld	de,dfcb
	call	initfcb
	call	f$open
	jr	z,opnok
	call	print
	db	cr,lf
	db	'*** cannot open file ***',cr,lf,0
	jp	nextf
;
opnok:	ld	hl,(buffer)	;get start of buffer
svlp:	ld	bc,dbuf
..sav:	ld	a,(hl)
	ld	(bc),a
	inc	hl
	inc	c
	jr	nz,..sav
	ld	de,dfcb
	call	f$write
	jr	nz,wrerr
	ld	de,(eofptr)
	push	hl
	sbc	hl,de
	pop	hl
	jr	nz,svlp
	ld	de,dfcb
	call	f$close
	inc	de
	call	pfn2
	call	print
	db	' written back, all modules serialized ',0
	ld	hl,(newo)
	call	phlfdc
	ld	a,'/'
	call	cout
	ld	hl,(newu)
	call	phlfdc
	call	crlf
	jp	nextf
;
wrerr:	call	print
	db	cr,lf
	db	'*** write error - aborted ***',cr,lf,0
	jp	nextf
;
ckntry:	call	get2		;get type
	or	a		;absolute?
	jr	z,abs
	call	get8
	call	get8
	jp	skipn
;
abs:	ld	hl,(bitml)
	ld	(savml),hl
	ld	a,(bithi)
	ld	(savhi),a
	call	get8		;get first half
	call	get8		;get second half
	call	dspnam
	ld	hl,nme
	ld	de,orig
	ld	b,7
	call	compb
	ld	de,(newo)
	jr	z,chg
	ld	de,unit
	call	compb
	jp	nz,eval
	ld	de,(newu)
chg:	ld	a,e		;get low byte
	call	put8b		;stash 8 bits into REL file
	ld	a,d		;get high byte
	call	put8b
	ld	a,1
	ld	(chgd),a
	jp	eval
;
put8b:	push	de		;save word
	ld	e,a		;save byte
	ld	a,(savhi)
	ld	d,a
	ld	hl,(savml)
	ld	b,8		;8 bits to process
..put:	rlc	e		;put bit in position
	ld	a,e		;get byte
	and	1		;isolate bit
	ld	c,a
	call	putbit
	call	incbit		;point to next bit in file
	djnz	..put		;do it 8 times
	ld	a,1
	ld	(rsmod),a	; set "module reserialized" flag
	ld	(savml),hl
	ld	a,d
	ld	(savhi),a
	pop	de
	ret
;
name:	xor	a
	ld	(rsmod),a	; reset flag
	call	dspnam1
	jp	eval
;
dspnam1:exx
	ld	l,0
	jr	.dsp..
;
dspnam:	exx
	ld	l,1
.dsp..:	exx
	ld	e,0
	call	get3		;get name length
	ld	iy,nme
	ld	b,a		;length into b
namelp:	push	bc
	call	get8		;get a byte
	exx
	bit	0,l
	exx
	call	z,cout
	ld	(iy+0),a
	inc	iy
	pop	bc
	djnz	namelp
	ld	(iy+0),0
	ret
;
skpvn:	call	skpval
;
; skip a name
;
skipn:	ld	e,0
	call	get3		;get name field length
	ld	b,a		;length into b
skipnl:	push	bc
	call	get8		;swallow 8 bits
	pop	bc
	djnz	skipnl
	jp	eval
;
skpval:	ld	e,0
	call	get2
	call	get8
;
; the following routines return 1,2,3,4, or 8 bits in A.
; when calling, E must be zero!
;
get8:	call	get4
	ld	e,a
get4:	call	get3
	ld	e,a
	jr	get1
;
; get next 3 bits into A
;
get3:	call	get2		;get 2 bits
	ld	e,a
	jr	get1
;
; get next 2 bits into A
;
get2:	call	get1
	ld	e,a
get1:	ld	a,(bithi)
	ld	d,a
	ld	hl,(bitml)
	call	getbit
	rlc	e
	or	e
	push	af
	call	incbit
	ld	(bitml),hl
	ld	a,d
	ld	(bithi),a
	pop	af
	ld	e,0		;make this re-entrant
	ret
;
incbit:	inc	hl
	ld	a,h
	or	l
	ret	nz
	inc	d
	ret
;
notfnd:	call	print
	db	'File not found',cr,lf,0
	jp	nextf
;
finish:	call	print
	db	cr,lf,lf
	db	'*** all done ***',cr,lf,0
	rst	0
;
nofile:	call	print
	db	'No file specified',cr,lf,lf
	db	'Usage:',cr,lf
	db	'0A}RS FILENAME[.REL]',cr,lf
	db	'program prompts for input',cr,lf
	db	'NOTE: the author cannot assume any liability',cr,lf
	db	'for copyright violation by the user!',cr,lf,lf,0
	rst	0
;
	dseg
;
nme:	ds	10
orig:	db	'?ORIG?',0
unit:	db	'?UNIT?',0
rsmod:	db	0
rsedy:	db	' reserialized.',0
rsedn:	db	' unserialized.',0
chgd:	db	0
newo:	dw	1111h
newu:	dw	2222h
fnbuf:	dw	0
files:	dw	0
buffer:	dw	0
eofptr:	dw	0
bitml:	dw	0		;bit address medium+low
bithi:	db	0		;bit address high
savml:	dw	0
savhi:	db	0
	ds	80
stack	equ	$
	end
d	e,a