;       xsub  'Extended Submit Facility'  version 2.2
;
;
;
;	xsub loads below ccp, and feeds command lines to
;	programs which read buffered input
;
bias	equ	0000h	;bias for relocation
base	equ	0ffffh	;no intercepts below here
wboot	equ	0000h
bdos	equ	0005h
bdosl	equ	bdos+1
dbuff	equ	0080h
;
cr	equ	0dh	;carriage return
lf	equ	0ah	;line feed
modnum	equ	14	;module number position
pbuff	equ	9	;print buffer
rbuff	equ	10	;read buffer
openf	equ	15	;open file
closef	equ	16	;close file
delf	equ	19	;delete file
dreadf	equ	20	;disk read
dmaf	equ	26	;set dma function
;
;
	org	0000h+bias
;	initialize jmps to include xsub module
	jmp	start
	ds	3
trapjmp:
	jmp	trap
	db	'xsub'
start:
	lhld	wboot+1
	shld	savboot
	lxi	h,wstart
	shld	wboot+1
	lhld	bdosl
	shld	rbdos+1	;real bdos entry
	lxi	h,trapjmp	;address to fill
	shld	bdosl	;jmp @0005 leads to trap
	pop	h	;ccp return address
	shld	ccpret
	pchl		;back to ccp
;
savboot:
	ds	2	;warm boot saved and restored at end
			;of submit file
;
wstart:
	lxi	sp,stack
	mvi	c,pbuff	;print message
	CALL	GET$SUBADDR
	lxi	d,actmsg
Š	CNZ	rbdos
	lxi	h,dbuff	;restore default buffer
	shld	udma
	call	rsetdma
	lxi	h,trapjmp
	shld	bdosl	;fixup low jump address
	lhld	ccpret	;back to ccp
	pchl

actmsg:	db	cr,lf,'(xsub active)$'
;
trap:	;arrive here at each bdos call
	pop	h	;return address
	push	h	;back to stack
	mov	a,h	;high address
	cpi	base shr 8
	jnc	rbdos	;skip calls on bdos above here
	mov	a,c	;function number
	cpi	rbuff
	jz	rnbuff	;read next buffer
	cpi	dmaf	;set dma address?
	jnz	rbdos	;skip if not
	xchg		;dma to hl
	shld	udma	;save it
	xchg
rbdos:	jmp	0000h	;filled in at initialization
;
setdma:
	lxi	d,combuf
SETDMA1:
	mvi	c,dmaf
	JMP	RBDOS
;
rsetdma:
	lhld	udma
	xchg
	JMP	SETDMA1
;
GET$SUBADDR:
	LHLD	RBDOS+1
	MVI	L,09H
	MOV	E,M
	INX	H
	MOV	D,M
	XCHG
	MOV	A,M
	ORA	A
	RET
;
DELETE$SUB:
	CALL 	GET$SUBADDR
	MVI	M,0
	MVI	C,DELF
	LXI	D,SUBFCB
;
Šfbdos:
	push	b
	push	d
	call	setdma
	pop	d
	pop	b
	call	rbdos
	push	psw
	call	rsetdma
	pop	psw
	ret
;
cksub:	;check for sub file present
	CALL	GET$SUBADDR
	RZ
	INX	H
	LXI	D,SUBS1
	MVI	C,20
;
MOVE:
	INR	C
MOVE1:
	ORA	C
	DCR	C
	RZ
	MOV	A,M
	STAX	D
	INX	H
	INX	D
	JMP	MOVE1
;
rnbuff:
	push	d	;command address
	call	cksub	;sub file present?
	pop	d
	mvi	c,rbuff
	ORA	A
	jz	restor	;no sub file 
;
	push	d
	lda	subrc	;length of file
	ora	a	;zero?
	jz	rbdos	;skip if so
	dcr	a	;length - 1
	sta	subcr	;next to read
	mvi	c,dreadf
	lxi	d,subfcb
	call	fbdos	;read record
	ORA	A
	JZ	READOK

	CALL	DELETE$SUB
	MVI	C,0
restor:
	lhld	savboot
Š	shld	wboot+1
	jmp	rbdos

READOK:
;	now print the buffer with cr,lf

	lxi	h,combuf
	mov	e,m	;length
	mvi	d,0	;high order 00
	dad	d	;to last character position
	inx	h
	mvi	m,cr
	inx	h
	mvi	m,lf
	inx	h
	mvi	m,'$'
	mvi	c,pbuff
	lxi	d,combuf+1
	LDAX	D
	CPI	3
	CNZ	rbdos	;to print it
	pop	h	;.max length
	lxi	d,combuf
	ldax	d	;how long?
	cmp	m	;cy if ok
	jc	movlin
	mov	a,m	;max length
	stax	d	;truncate length
movlin:
	mov	c,a	;length to c
	inr	c	;+1
	inx	h	;to length of line
	XCHG
	CALL	MOVE
	CALL 	GET$SUBADDR

	PUSH	H	;.SUBFLAG
	INX	H	;.FCB(S1)
	INX	H	;.FCB(S2)
	INX	H	;.FCB(RC)
	DCR	M
	POP	H
	CZ	DELETE$SUB
	LDA	COMBUF+1	;^C?
	CPI	3
	RNZ
	MVI	C,PBUFF
	LXI	D,CTLCMSG
	CALL	RBDOS
	JMP	WBOOT
;
subfcb:
	db	1	;a:
	db	'$$$     '
	db	'SUB'
Š	db	0
SUBS1:	
	DB	0,0
subrc:
	ds	1
	ds	16	;map
subcr:	ds	1
;
CTLCMSG:DB	'^C$'
combuf:	ds	131
udma:	dw	dbuff
ccpret:	ds	2	;ccp return address
	ds	24	;12 level stack
stack:
	end