title Block Move Routines for the 6545 CRT Controller.  (C) 1983 By NLS
.comment %
########################################################
##                                                    ##
##      KAYPRO 10 System                              ##
##                                                    ##
##      By M. Sherman                                 ##
##                                                    ##
##      block move routines for the 6545              ##
##                                                    ##
##      Copyright (C) 1983 By Non-Linear Systems, Inc ##
##      No warranty is made, expressed or implied.    ##
##                                                    ##
########################################################
##      Date: 03/28/83                    [77]        ##
########################################################

	Current revision:	7.7		28-Mar-83
	Previous revision:	7.6		11-Mar-83
	Prev. working rev.:	7.5		14-Feb-83
		Changes:  Attempt to add insert line.
		 (revision 7.5)
		Changes:  Updated scrolling (movsts), insert
		 line (revision 7.6)
		Changes:  Final modifications and debugging
		 prior to shipping (version 7.7)

includes the following routines:

MOVSTS:		move status line (if preserved=true), scroll screen
MDIR:		move data with attributes (emulates Z-80 LDIR)
MDDR:		move data with attributes (emulates Z-80 LDDR)
DLTLIN:		delete the current cursor line.
INSLIN:		insert a line at the current cursor location.
%
page

extrn	clrdis, regrst, carret, clreol, putcur
extrn	cursor, ccol, crow, vrbase, vatt

public	mdir, mddr, movsts, dltlin, inslin

vcdata	equ	1fh		; video ram data port
vccmd	equ	1ch		; register select port
vcstat	equ	1ch		; vc status port
scrcmd	equ	0c1ch		; used with regrst to alter base address
rwcmd	equ	121ch		; used with regrst to set up data address
strcmd	equ	1fh		; 'tickle', 'dummy' or strobe register.
lastlin	equ	0730h		; beginning address of last line (except stat)
linesiz	equ	80		; line length in counting numbers
bufsiz	equ	linesiz		; buffer size, if any
hiadd	equ	12h		; high byte of data address port
loadd	equ	13h		; low byte of data address port
vcrdat	equ	vccmd+1		; video controller register data port
linesps	equ	24

.Z80

page

; move status line and scroll
;

movsts:	ld	a,(vatt)	; first, check to see if the status line
	and	20h		; is to be preserved or not.
	jr	z,mvsts2	; if bit 5 is zero, no. else...
; status line preservation is TRUE.  Move the status line before doing
; anything else.
;
mvsts:	ld	hl,(vrbase)
	ld	de,lastlin+linesiz
	ld	bc,linesiz	; amount to move
	add	hl,de		; hl=source, de=statline
	ld	a,h		; qualify it
	and	07h
	ld	h,a
	ld	d,h		; copy it into de,
	ld	e,l		; de=source.
	add	hl,bc		; de=source, hl=destination
	ld	a,h		; qualify it
	and	07h
	ld	h,a
	ex	de,hl		; hl=source, de=destination
	push	hl		; save status line address
	call	mdir		; if so, move it
	pop	de		; status line address in de
	ld	hl,linesiz	; amount to clear
	call	clrdis		; clear it
	ld	hl,(vrbase)
	ld	de,linesiz
	add	hl,de
	ld	a,h
	and	07h
	ld	h,a
	ld	(vrbase),hl
	ex	de,hl
	ld	bc,scrcmd
	jp	regrst		; scroll screen and exit

; enter here for scroll if status line preservation IS NOT enabled.
; MVSTS2 scrolls the screen, then clears the status line.
;
mvsts2:	ld	hl,(vrbase)
	ld	de,linesiz
	add	hl,de
	ld	a,h
	and	07h
	ld	h,a
	ld	(vrbase),hl	; new base address
	ex	de,hl
	ld	bc,scrcmd
	call	regrst
	ld	hl,(vrbase)
	ld	de,linesps*linesiz	; starting addr., status line
	add	hl,de
	ld	a,h
	and	07h
	ld	h,a
	ex	de,hl
	ld	hl,linesiz
	jp	clrdis			; clear status line, exit.

; move a block of data, source in hl, destination in de, count in bc.
; (just like a Z-80 block move, or LDIR, command, only slower.)
;

mdir:	ld	a,b
	and	07h		; qualify the upper byte,
	or	c		; qualify the count
	ret	z		; not 65,535 please!
mdir2:	push	bc		; save the count
rdlopx:	in	a,(vcstat)
	or	a
	jp	p,rdlopx	; wait until ready to begin
	ld	bc,hiadd*100H+loadd	; address register numbers
			; change the data update address register:
	ld	a,b		; high address byte register, UA,
	out	(vccmd),a	; select it.
	ld	a,h		; get high byte, new address,
	out	(vcrdat),a	; put it in high byte, UA.
	ld	a,c		; low address byte, UA,
	out	(vccmd),a	; select it.
	ld	a,l		; new low address byte,
	out	(vcrdat),a	; set it.
	ld	a,strcmd	; strobe register
	out	(vccmd),a	; start a new cycle
rdlop1:	in	a,(vcstat)	; get status
	or	a		; set flags
	jp	p,rdlop1	; wait until vc is ready
	in	a,(vcdata)	; get a data byte
	ex	af,af'		; save it
	ld	a,b		; change address,
	out	(vccmd),a
	ld	a,d
	out	(vcrdat),a
	ld	a,c
	out	(vccmd),a
	ld	a,e
	out	(vcrdat),a
	ld	a,strcmd
	out	(vccmd),a
	ex	af,af'
	out	(vcdata),a
	inc	de
	inc	hl
	ld	a,d
	and	7h
	ld	d,a
	ld	a,h
	and	7h
	ld	h,a
; and now for the attributes
rdlop2:	in	a,(vcstat)
	or	a
	jp	p,rdlop2
	ld	a,b		; change address,
	out	(vccmd),a
	ld	a,h
	or	08h		; go to attribute ram
	out	(vcrdat),a
	ld	a,c
	out	(vccmd),a
	ld	a,l
	out	(vcrdat),a
	ld	a,strcmd
	out	(vccmd),a
rdlop3:	in	a,(vcstat)
	or	a
	jp	p,rdlop3
	in	a,(vcdata)
	ex	af,af'
	ld	a,b		; change address,
	out	(vccmd),a
	ld	a,d
	or	08h		; attribute ram
	out	(vcrdat),a
	ld	a,c
	out	(vccmd),a
	ld	a,e
	out	(vcrdat),a
	ld	a,strcmd
	out	(vccmd),a
	ex	af,af'
	out	(vcdata),a
	pop	bc
	dec	bc
	ld	a,b
	or	c
	jp	nz,mdir2
	jp	mdexlp		; make sure last byte got moved

; move a block of data, source in hl, destination in de, count in bc.
; (just like a Z-80 block move, or LDDR, command, only slower.)
;

mddr:	ld	a,b
	and	07h		; qualify the upper byte,
	or	c		; qualify the count
	ret	z		; not 65,535 please!
mddr2:	push	bc		; save the count
ddlopx:	in	a,(vcstat)
	or	a
	jp	p,ddlopx	; wait until ready to begin
	ld	bc,hiadd*100H+loadd	; address register numbers
			; change the data update address register:
	ld	a,b		; high address byte register, UA,
	out	(vccmd),a	; select it.
	ld	a,h		; get high byte, new address,
	and	07h		; qualify it
	out	(vcrdat),a	; put it in high byte, UA.
	ld	a,c		; low address byte, UA,
	out	(vccmd),a	; select it.
	ld	a,l		; new low address byte,
	out	(vcrdat),a	; set it.
	ld	a,strcmd	; strobe register
	out	(vccmd),a	; start a new cycle
ddlop1:	in	a,(vcstat)	; get status
	or	a		; set flags
	jp	p,ddlop1	; wait until vc is ready
	in	a,(vcdata)	; get a data byte
	ex	af,af'		; save it
	ld	a,b		; change address,
	out	(vccmd),a
	ld	a,d
	and	07h
	out	(vcrdat),a
	ld	a,c
	out	(vccmd),a
	ld	a,e
	out	(vcrdat),a
	ld	a,strcmd
	out	(vccmd),a
	ex	af,af'
	out	(vcdata),a
	inc	de
	inc	hl
	ld	a,d
	and	7h
	ld	d,a
	ld	a,h
	and	7h
	ld	h,a
; and now for the attributes
ddlop2:	in	a,(vcstat)
	or	a
	jp	p,ddlop2
	ld	a,b		; change address,
	out	(vccmd),a
	ld	a,h
	or	08h		; go to attribute ram
	out	(vcrdat),a
	ld	a,c
	out	(vccmd),a
	ld	a,l
	out	(vcrdat),a
	ld	a,strcmd
	out	(vccmd),a
ddlop3:	in	a,(vcstat)
	or	a
	jp	p,ddlop3
	in	a,(vcdata)
	ex	af,af'
	ld	a,b		; change address,
	out	(vccmd),a
	ld	a,d
	or	08h		; attribute ram
	out	(vcrdat),a
	ld	a,c
	out	(vccmd),a
	ld	a,e
	out	(vcrdat),a
	ld	a,strcmd
	out	(vccmd),a
	ex	af,af'
	out	(vcdata),a
	pop	bc
	dec	hl
	dec	hl
	dec	de
	dec	de
	dec	bc
	ld	a,b
	or	c
	jp	nz,mddr2
mdexlp:	in	a,(vcstat)
	or	a
	jp	p,mdexlp
	ret

dltlin:	call	carret		; do a carriage return
	ld	a,(crow)
	or	a
	jp	z,dscroll	; special scroll
	ld	de,(cursor)
	ld	hl,linesiz
	cp	23
	jp	nc,clrdis	; clear last line or status line, exit
	cp	11
	jr	nc,dltl1a	; normal delete line, lines 11-22
	ex	de,hl		; de=linesiz, hl=cursor
	ld	bc,linesiz-1
	add	hl,bc		; hl=end of current line=dest
	ld	a,h
	and	07h		; qualify it
	ld	h,a		; hl=dest.
	ld	b,h
	ld	c,l		; bc=dest.
	sbc	hl,de		; hl=source
	ld	a,h
	and	7h		; qualify it
	ld	h,a		; source in hl
	push	hl		; save source
	ld	de,(vrbase)
	sbc	hl,de		; hl=source-vrbase
	jr	nc,dltl2b	; true count if no carry
	ld	hl,0800h
	or	a		; clear carry
	sbc	hl,de
	pop	de		; source in de
	add	hl,de		; count in hl
	ld	a,h
	and	07h
	ld	h,b
	ld	b,a
	ld	a,l
	ld	l,c
	ld	c,a
	ex	de,hl		; hl=source, de=dest., bc=count
dscrla:	inc	bc		; count=count-1
	call	mddr
dscroll:call	mvsts		; scroll, saving status line
	ld	hl,(cursor)
	ld	de,linesiz
	add	hl,de
	ex	de,hl		; new cursor position in de
	jp	putcur		; place cursor and exit

dltl2b:	ld	d,b
	ld	e,c		; de=dest.
	ld	b,h
	ld	c,l		; bc=count
	pop	hl		; hl=source
	jr	dscrla		; go do it

dltl1a:	add	hl,de		; source = linesiz+destination
	ld	a,h
	and	7h		; qualify it,
	ld	d,a
	ld	e,l		; put source in de.
	ld	hl,(vrbase)
	ld	bc,lastlin+linesiz
	add	hl,bc		; lastpos=vrbase+(lastlin+linesiz)
	ld	a,h
	and	07h		; qualify it,
	ld	h,a		; put it back in hl,
	ld	b,a
	ld	c,l		; save lastpos in bc.
	sbc	hl,de		; hl=lastpos-source
	jr	nc,dltl3a	; valid if no carry,
	ld	hl,0800h	; else put boundry in hl,
	or	a		; clear carry
	sbc	hl,de		; hl=boundry-source
	add	hl,bc		; +lastpos
dltl3a:	ld	b,h		; put count in bc
	ld	c,l
	ld	hl,(cursor)	; dest
	ex	de,hl		; in de, source in hl
	call	mdir		; move it.
	ld	hl,(vrbase)
	ld	de,lastlin
	add	hl,de
	ld	a,h
	and	07h
	ld	d,a
	ld	e,l		; last line in de
	ld	hl,linesiz
	jp	clrdis		; clear the last line

; insert a line

inslin:	ld	a,(crow)
	cp	12
	jp	nc,insln2	; 'normal' insert line
	ld	hl,(vrbase)	; source
	ld	de,linesiz
	or	a		; clear carry
	sbc	hl,de		; hl = new vrbase
	ld	a,h
	and	07h		; qualify it
	ld	h,a
	ex	de,hl		; dest in de,
	ld	bc,scrcmd	; scroll
	call	regrst
	ld	hl,(cursor)
	ld	bc,(vrbase)
	or	a
	sbc	hl,bc
	jr	nc,insl2a	; hl=amount
	ld	hl,0800h
	or	a		; clear carry flag
	sbc	hl,bc		; hl=800h-source
	ld	a,h
	and	07h
	ld	h,a
	ld	bc,(cursor)
	add	hl,bc
insl2a:	ld	a,h
	and	07h
	ld	b,a
	ld	c,l		; amount in bc
; test
	ld	hl,80+48
	add	hl,bc
	ld	a,h
	and	07h
	ld	b,a
	ld	c,l
;
	ld	hl,(vrbase)	; source in hl
; test
	ld	de,23*linesiz
	add	hl,de
	ld	a,h
	and	07h
	ld	h,a
	ex	de,hl
	ld	hl,80
	add	hl,de		; source in hl, dest in de
	ld	a,h
	and	07h
	ld	h,a
;
	call	mdir
	ld	hl,(cursor)
	ld	bc,linesiz
	or	a		; clear carry
	sbc	hl,bc
	ld	a,h
	and	07h
	ld	h,a		; qualify address
	ex	de,hl		; put in de
	ld	a,(ccol)
	ld	c,a
	ld	b,0
	ld	hl,linesiz
	sbc	hl,bc		; hl=amount
	push	de		; save new cursor address
	push	hl
	call	clrdis		; clear to end of inserted line
	pop	bc		; amount
	push	bc
	ld	hl,(cursor)
	ld	a,(ccol)
	ld	e,a
	ld	d,0
	or	a
	sbc	hl,de
	ld	a,h
	and	07h
	ld	d,a
	ld	e,l		; dest in de
	ld	hl,(cursor)	; source in hl
	call	mdir
	pop	bc		; amount
	ld	hl,linesiz
	or	a
	sbc	hl,bc
	call	nz,clrdis
	ld	hl,(vrbase)
	ld	bc,linesiz
	or	a
	sbc	hl,bc
	ld	a,h
	and	07h
	ld	h,a
	ld	(vrbase),hl	; new vr base, 
	pop	de
	jp	putcur		; put cursor and exit

insln2:	sub	22
	jr	z,inl33
	jp	nc,clreol
	neg			; two's complement, number of lines to move
	push	af
	ld	hl,(vrbase)
	ld	de,79+22*80	; source
	ld	bc,80
	add	hl,de
	ld	a,h
	and	07h
	ld	d,a
	ld	e,l
	add	hl,bc		; destination
	ld	a,h
	and	07h
	ld	h,a
	ex	de,hl		; hl:=source, de:=dest.
	pop	af
	push	hl
	ld	hl,0
inl22:	add	hl,bc
	dec	a
	jr	nz,inl22
	ld	b,h
	ld	c,l		; bc=amount
	pop	hl		; restore source to hl
	call	mddr		; move them
inl33:	ld	hl,(cursor)	; source in de,
	ld	d,h
	ld	e,l
	ld	a,(ccol)
	ld	c,a		; amount to clear, next line
	ld	a,80
	sub	c		; amount to move and distance to go
	ld	c,a
	ld	b,0
	add	hl,bc		; dest. in hl,
	ld	a,h
	and	07h
	ld	h,a
	ex	de,hl		; now hl=source, de=dest, bc=amount
	call	mdir		; move the rest to beginning of next line
	ld	a,(ccol)
	ld	l,a
	ld	h,0
	or	a
	call	nz,clrdis	; clear to the end of the next line,
	jp	clreol		; clear to the end of this one.

	defw	0000h

END