From f510da9d4662ed6e27ac37bb661edc382f5c1ebb Mon Sep 17 00:00:00 2001
From: wayne <wayne@1438685a-98c7-b363-4179-13d573978243>
Date: Fri, 23 Nov 2012 14:05:57 +0000
Subject: [PATCH] Reintegrate dwg -> trunk

---
 Source/n8v.asm | 826 ++++++++++++++++++++++++++++---------------------
 1 file changed, 471 insertions(+), 355 deletions(-)

diff --git a/Source/n8v.asm b/Source/n8v.asm
index 857fc07d..0e483cca 100644
--- a/Source/n8v.asm
+++ b/Source/n8v.asm
@@ -1,15 +1,21 @@
+; ../RomWBW/Source/n8v.asm 11/22/2012 dwg - best so far
+; ../RomWBW/Source/n8v.asm 11/19/2012 dwg - add snippets into video scheme
 ; ../RomWBW/Source/n8v.asm 11/16/2012 dwg - N8V_VDAQRY now working
 ; ../RomWBW/Source/n8v.asm 11/15/2012 dwg - vdaini and vdaqry retcodes ok
 ; ../RomWBW/Source/n8v.asm 10/28/2012 dwg - add n8v_modes
 ; ../RomWBW/Source/n8v.asm 10/27/2012 dwg - begin enhancement
 
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+; N8 VIDEO DRIVER FOR ROMWBW ;
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; 
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+; Video Display Processor I/O Addresses for the TMS9918 ;
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+BASE:   .EQU    128
+CMDP:   .EQU    BASE+25
+DATAP:  .EQU    BASE+24
 
-;__N8VDRIVER_______________________________________________________________________________________
-;
-;	N8 VIDEO DRIVER FOR ROMWBW
-;
-;__________________________________________________________________________________________________
-;
 ;__________________________________________________________________________________________________
 ; DATA CONSTANTS
 ;__________________________________________________________________________________________________
@@ -18,33 +24,262 @@
 ; BOARD INITIALIZATION
 ;_________________________________________________________________________
 
-;
-; This routine is called from bnk1.asm to init the TMS9918
-; If HL is non-zero, it specifies the character bitmaps to load
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+; This routine is called from bnk1.asm to init the TMS9918		;
+; If HL is non-zero, it specifies the character bitmaps to load ;
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 N8V_VDAINI:
-
 	LD	A,C
 	LD	(VDP_DEVUNIT),A
 	LD	A,E
 	LD	(VDP_MODE),A
 	PUSH	HL
-    CALL    VDP_CLR16K	; clear first 16K of TMS9918 video ram to zeroes
-    CALL    VDP_SETREGS	; set TMS9918 into Text Mode
-    CALL    VDP_MODES	; set TMS9918 into 40-column mode
-    CALL    VDP_PNT		; set TMS9918 Pattern Name Table Pointer
-    CALL    VDP_PGT		; set TMS9918 Pattern Generator Table Pointer
-    CALL    VDP_COLORS	; set TMS9918 foreground(white) background(black)
+	; Fall through...
+
+	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+	; clear first 16K of TMS9918 video ram to zeroes ;
+	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+	LD      C,CMDP
+    LD      A,$00
+    OUT     (C),A           ; out(CMDP,0);
+	CALL	RECOVER
+    LD      A,64
+    OUT     (C),A           ; out(CMDP,64);
+	CALL	RECOVER
+	;
+	LD	C,DATAP
+	LD	HL,16384
+CLR16LOOP:
+	LD	A,0
+	OUT	(C),A
+	DEC	HL
+	LD	A,H
+	OR	L
+	JR	NZ,CLR16LOOP
+
+	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+	; Set TMS9918 into Text Mode ;
+	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+    LD      C,CMDP
+    LD      A,0
+    OUT     (C),A           ; out(CMDP,0);
+	CALL	RECOVER
+    LD      A,128
+    OUT     (C),A           ; out(CMDP,128);
+	CALL	RECOVER
+
+	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+	; Set TMS9918 into 40-column mode ;
+	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+	LD      C,CMDP
+    LD      A,80
+    OUT     (C),A           ; out(CMDP,80);
+	CALL	RECOVER
+    LD      A,129
+    OUT     (C),A           ; out(CMDP,129);
+	CALL	RECOVER
+	;
+	;; text mode is 24x40
+	LD		A,0
+	LD		(VDP_MODE),a
+	LD		a,40
+	LD		(VDP_COLS),a
+	LD		a,24
+	LD		(VDP_ROWS),A
+
+;;    CALL    VDP_PNT		; set TMS9918 Pattern Name Table Pointer
+;VDP_PNT:
+	LD      C,CMDP
+    LD      A,0
+    OUT     (C),A           ; out(CMDP,0);
+	CALL	RECOVER
+    LD      A,130
+    OUT     (C),A           ; out(CMDP,130);
+    CALL	RECOVER
+
+;;    CALL    VDP_PGT		; set TMS9918 Pattern Generator Table Pointer
+;VDP_PGT:
+	LD      C,CMDP
+    LD      A,1
+    OUT     (C),A           ; out(CMDP,1);
+	CALL	RECOVER
+	LD      A,132
+    OUT     (C),A           ; out(CMDP,132);
+	CALL	RECOVER
+
+;;    CALL    VDP_COLORS	; set TMS9918 foreground(white) background(black)
+;VDP_COLORS:
+	LD      C,CMDP
+    LD      A,(VDP_ATTR)
+;       LD      A,240
+    OUT     (C),A           ; out(CMDP,240); 240 is 0xF0 - 1111 0000 LSB=background MSB=foreground
+	CALL	RECOVER
+    LD      A,135
+    OUT     (C),A           ; out(CMDP,135);
+    CALL	RECOVER
+
+
 	POP		HL
 	LD		A,L
 	OR		H
 	JP		Z,N8V_NOLOAD
-    CALL    VDP_LOAD2   ; set TMS9918 character bitmaps
+;;    CALL    VDP_LOAD2   ; set TMS9918 character bitmaps
+;VDP_LOAD2:
+        LD      C,CMDP
+        LD      A,0
+        OUT     (C),A           ; out(CMDP,0);
+		CALL	RECOVER
+        LD      A,72
+        OUT     (C),A           ; out(CMDP,72);
+		CALL	RECOVER
+        LD      DE,256
+		LD		C,DATAP
+VDP_LOAD2LOOP:
+        LD      A,(HL)
+        LD      (BYTE8),A
+        INC     HL
+        LD      A,(HL)
+        LD      (BYTE7),A
+        INC     HL
+        LD      A,(HL)
+        LD      (BYTE6),A
+        INC     HL
+        LD      A,(HL)
+        LD      (BYTE5),A
+        INC     HL
+        LD      A,(HL)
+        LD      (BYTE4),A
+        INC     HL
+        LD      A,(HL)
+        LD      (BYTE3),A
+        INC     HL
+        LD      A,(HL)
+        LD      (BYTE2),A
+        INC     HL
+        LD      A,(HL)
+        INC     HL
+        OUT     (C),A
+		CALL	RECOVER
+        LD      A,(BYTE2)
+		OUT	(C),A
+		CALL	RECOVER
+        LD      A,(BYTE3)
+        OUT     (C),A
+		CALL	RECOVER
+        LD      A,(BYTE4)
+        OUT     (C),A
+		CALL	RECOVER
+        LD      A,(BYTE5)
+        OUT     (C),A
+		CALL	RECOVER
+        LD      A,(BYTE6)
+        OUT     (C),A
+		CALL	RECOVER
+        LD      A,(BYTE7)
+        OUT     (C),A
+		CALL	RECOVER
+		LD      A,(BYTE8)
+        OUT     (C),A
+		CALL	RECOVER
+        DEC	DE
+		LD	A,D
+		OR	E
+        JR      NZ,VDP_LOAD2LOOP
 N8V_NOLOAD:
- 	CALL	VDP_SINE	; display init message on composite video
+; fall through...
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+; Display init message on composite video ;
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+	; Output "N8-2312 TMS9918 Text Mode Init Done!"
+	LD	HL,0
+	CALL	VDP_WRVRAM
+    LD      HL,VDP_HELLO
+    LD      DE,39
+    LD      C,DATAP
+HELLO_LOOP:
+    LD      A,(HL)
+    OUT     (C),A
+    INC     HL
+    DEC     DE
+    LD      A,D
+    OR      E
+    JR      NZ,HELLO_LOOP
+	;
+	; N8VEM HBIOS v2.2 B3
+	LD	HL,40+40+40+40+3
+	CALL	VDP_WRVRAM
+	LD	HL,STR_BANNER
+	LD	C,DATAP
+	LD	DE,20
+BAN_LOOP:
+	LD	A,(HL)
+	CP	'('
+	JP	Z,BAN_DONE
+	OUT	(C),A
+	INC	HL
+	DEC	DE
+	LD	A,D
+	OR	E
+	JR	NZ,BAN_LOOP
+BAN_DONE:
+	;
+	; (rOMwbw-DOUG-121113t0113) <BLANK>
+	LD	HL,40+40+40+40+40+3
+	CALL	VDP_WRVRAM
+	;
+	LD	HL,STR_BANNER + 20
+	LD	C,DATAP
+	;
+	LD	DE,27
+BAN_LOOP2:
+	LD	A,(HL)
+	CP	' '
+	JP	Z,BAN_DONE2
+	OUT	(C),A
+	INC	HL
+	DEC	DE
+	LD	A,D
+	OR	E
+	JR	NZ,BAN_LOOP2
+	LD	A,'|'
+	OUT	(C),A
+	CALL	RECOVER
+BAN_DONE2:
+	;
+	; n8 z180 sbc, floppy (autosize), ppide..
+	PUSH	HL
+	LD	HL,40+40+40+40+40+40+3
+	CALL	VDP_WRVRAM
+	POP	HL
+	;
+	LD	C,DATAP
+	LD	DE,60
+BAN_LOOP3:
+	LD	A,(HL)
+	CP	'$'
+	JP	Z,BAN_DONE3
+	OUT	(C),A
+	INC	HL
+	DEC	DE
+	LD	A,D
+	OR	E
+	JP	NZ,BAN_LOOP3
+BAN_DONE3:
+; fall through...
+
 	CALL	PPK_INIT
+	; fall through...
+
 	XOR	A
 	RET
 
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+; This is the end of the init routine ;
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+
 ;__________________________________________________________________________________________________
 ; CHARACTER I/O (CIO) DISPATCHER
 ;__________________________________________________________________________________________________
@@ -104,24 +339,23 @@ N8V_DISPVDA:
 	JP	Z,PPK_READ
 	CALL	PANIC
 
-
-
-
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+; Video Display Processor Query ;
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 N8V_VDAQRY:
-
 	LD	A,H
 	OR	L
 	JP	Z,N8V_QDONE
-		
+	;	
 	; read bitmaps and 
-        LD      C,CMDP
-        LD      A,0
-        OUT     (C),A           ; out(CMDP,0);
+    LD      C,CMDP
+    LD      A,0
+    OUT     (C),A           ; out(CMDP,0);
 	CALL	RECOVER
-        LD      A,72
-        OUT     (C),A           ; out(CMDP,72);
+    LD      A,72
+    OUT     (C),A           ; out(CMDP,72);
 	CALL	RECOVER
-
+	;
 	LD	DE,256
 	LD	C,DATAP
 	IN	A,(C)					; read status
@@ -130,58 +364,58 @@ VDP_QLOOP:
 	IN	A,(C)
 	CALL	RECOVER
 	LD	(BYTE8),A
-
+	;
 	IN	A,(C)
 	CALL	RECOVER
 	LD	(BYTE7),A
-
+	;
 	IN	A,(C)
 	CALL	RECOVER
 	LD	(BYTE6),A
-
+	;
 	IN	A,(C)
 	CALL	RECOVER
 	LD	(BYTE5),A
-
+	;
 	IN	A,(C)
 	CALL	RECOVER
 	LD	(BYTE4),A
-
+	;
 	IN	A,(C)
 	CALL	RECOVER
 	LD	(BYTE3),A
-
+	;
 	IN	A,(C)
 	CALL	RECOVER
 	LD	(BYTE2),A
-
+	;
 	IN	A,(C)
 	CALL	RECOVER
 ;	LD	(BYTE1),A
-
+	;
 	LD	(HL),A
 	INC	HL
-
+	;
 	LD	A,(BYTE2)
 	LD	(HL),A
 	INC	HL
-	
+	;
 	LD	A,(BYTE3)
 	LD	(HL),A
 	INC	HL
-
+	;
 	LD	A,(BYTE4)
 	LD	(HL),A
 	INC	HL
-
+	;
 	LD	A,(BYTE5)
 	LD	(HL),A
 	INC	HL
-
+	;	
 	LD	A,(BYTE6)
 	LD	(HL),A
 	INC	HL
-
+	;
 	LD	A,(BYTE7)
 	LD	(HL),A
 	INC	HL
@@ -204,325 +438,207 @@ N8V_QDONE:
 
 	LD	A,0		; return SUCCESS
 	RET
-	
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+; Video Display Processor Reset	;
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;	
 N8V_VDARES:
 	LD	HL,CHARSET
 	JP	N8V_VDAINI
-	
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;	
+; Video Display Processor Set Cursor Style ;
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 N8V_VDASCS:
 	CALL	PANIC
-	
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;	
+; Video Display Processor Set Cursor Position ;
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 N8V_VDASCP:
+	LD		A,E
+	LD		(VDP_COL),A		; keep private copy of column
+	LD		A,C
+	LD		(VDP_DEVUNIT),A		; keep private copy of dev/unit
+	LD		A,D
+	LD		(VDP_ROW),A		; keep private copy of row
 	XOR	A
 	RET
-	
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+; Video Display Processor Set Character Attributes ;
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;	
 N8V_VDASAT:
 	CALL	PANIC
-	
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+; Video Display Processor Set Color Color ;
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;	
 N8V_VDASCO:
 	CALL	PANIC
-	
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+; Video Display Processor Write Character ;
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;	
 N8V_VDAWRC:
-	XOR	A
-	RET
+	PUSH	DE
+
+	LD	hl,row_offs		; hl -> row offset table
+	LD	A,(VDP_ROW)		; pick up cursor row
+	LD	E,A				; place in LO byte of DE
+	LD	d,0				; make 16 bits
+	add	hl,DE			;
+	add hl,DE			; hl -> word in offset table for desired row
+	LD	e,(hl)			; pick up the LO byte of the row ptr
+	INC	HL
+	ld	d,(hl)			; pick up the HO byte of the ROW ptr
+	EX	DE,HL			; hl -> offset of first column in row
+	LD	A,(VDP_COL)		; pick up the current column number
+	LD	E,A				; use as LO byte of DE
+	LD	D,0				; make 16 bits
+	ADD	HL,DE			; hl = offset in name table of row and column
+	call VDP_WRVRAM		; set vram write ptr to proper byte in name table
+
+	POP	DE				; restore the output byte into E
+	LD	A,E				; move into A for output
+	LD	C,DATAP			; I/O address for subsequent VRAM write
+	OUT	(C),a			; prime the auto incrementer
+	OUT	(C),a			; output the data byte into the name table
 	
+	LD	A,(VDP_COL)
+	INC A
+	LD	(VDP_COL),A
+	CP	40
+	JR	NZ,N8V_VDAWRC2
+	LD	A,0
+	LD	(VDP_COL),A
+	LD	A,(VDP_ROW)
+	INC A
+	LD	(VDP_ROW),A
+	CP 24
+	JR	NZ, N8V_VDAWRC2
+	; need to scroll up one line
+	LD A,1				; SCROLL ONE LINE
+	LD E,A				; NEEDS TO BE IN A
+	CALL N8V_VDASCR		; USE SCROLLING FUNCTION
+N8V_VDAWRC2:	
+
+	XOR	A				; set SUCCESS return code
+	RET					; return from HBIOS call
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+; Video Display Processor Fill ;
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;	
 N8V_VDAFIL:
 	XOR	A
 	RET
-	
-N8V_VDASCR:
-  	XOR	A
-	RET
-
-;-------------------------------------------------
 
-BASE:   .EQU    128
-CMDP:   .EQU    BASE+25
-DATAP:  .EQU    BASE+24
-
-VDP_CLR16K:
-        LD      C,CMDP
-        LD      A,$00
-        OUT     (C),A           ; out(CMDP,0);
-        LD      A,64
-        OUT     (C),A           ; out(CMDP,64);
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;	
+; Video Display Processor Scroll ;
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+N8V_VDASCR:
+  	; E = scroll distance (# lines)
 
+	LD HL,0
+	CALL VDP_WRVRAM
 	LD	C,DATAP
-	LD	HL,16384
-CLR16LOOP:
-	LD	A,0
-	OUT	(C),A
-	DEC	HL
-	LD	A,H
-	OR	L
-	JR	NZ,CLR16LOOP
-
-        RET
-
-;-------------------------------------------------
-
-VDP_SETREGS:
-        LD      C,CMDP
-        LD      A,0
-        OUT     (C),A           ; out(CMDP,0);
-	NOP
-        LD      A,128
-        OUT     (C),A           ; out(CMDP,128);
-        RET
-
-;-------------------------------------------------
-
-; The only TMS9918 mode available right now is "text mode".
-
-VDP_MODES:
-        LD      C,CMDP
-        LD      A,80
-        OUT     (C),A           ; out(CMDP,80);
-		CALL	RECOVER
-        LD      A,129
-        OUT     (C),A           ; out(CMDP,129);
-		CALL	RECOVER
-
-	;; text mode is 24x40
-	LD	A,0
-	LD	(VDP_MODE),a
-	LD	a,40
-	LD	(VDP_COLS),a
-	LD	a,24
-	LD	(VDP_ROWS),A
-
-        RET
-
-;-------------------------------------------------
-
-VDP_PNT:
-        LD      C,CMDP
-        LD      A,0
-        OUT     (C),A           ; out(CMDP,0);
-	NOP
-        LD      A,130
-        OUT     (C),A           ; out(CMDP,130);
-        RET
-
-;-------------------------------------------------
-
-VDP_PGT:
-        LD      C,CMDP
-        LD      A,1
-        OUT     (C),A           ; out(CMDP,1);
-	NOP
-        LD      A,132
-        OUT     (C),A           ; out(CMDP,132);
-        RET
-
-;-------------------------------------------------
-
-VDP_COLORS:
-        LD      C,CMDP
-        LD      A,(VDP_ATTR)
-;       LD      A,240
-        OUT     (C),A           ; out(CMDP,240); 240 is 0xF0 - 1111 0000 LSB=background MSB=foreground
-	NOP
-        LD      A,135
-        OUT     (C),A           ; out(CMDP,135);
-        RET
-
-;-------------------------------------------------
-
-;-------------------------------------------------
-
-VDP_LOAD2:
-
-        LD      C,CMDP
-        LD      A,0
-
-        OUT     (C),A           ; out(CMDP,0);
-		CALL	RECOVER
-        LD      A,72
-        OUT     (C),A           ; out(CMDP,72);
-		CALL	RECOVER
-
-;		LD		A,H
-;		OR		L
-;		JP		NZ,NOLOAD2
-;		LD		HL,CHARSET
-;NOLOAD2:
-
-        LD      DE,256
-		LD		C,DATAP
-VDP_LOAD2LOOP:
-
-        LD      A,(HL)
-        LD      (BYTE8),A
-        INC     HL
-
-        LD      A,(HL)
-        LD      (BYTE7),A
-        INC     HL
-
-        LD      A,(HL)
-        LD      (BYTE6),A
-        INC     HL
-
-        LD      A,(HL)
-        LD      (BYTE5),A
-        INC     HL
-
-        LD      A,(HL)
-        LD      (BYTE4),A
-        INC     HL
-
-        LD      A,(HL)
-        LD      (BYTE3),A
-        INC     HL
-
-        LD      A,(HL)
-        LD      (BYTE2),A
-        INC     HL
-
-        LD      A,(HL)
-        INC     HL
-
-        OUT     (C),A
-	CALL	RECOVER
-        LD      A,(BYTE2)
-	OUT	(C),A
-	CALL	RECOVER
-        LD      A,(BYTE3)
-        OUT     (C),A
-	CALL	RECOVER
-        LD      A,(BYTE4)
-        OUT     (C),A
-	CALL	RECOVER
-        LD      A,(BYTE5)
-        OUT     (C),A
-	CALL	RECOVER
-        LD      A,(BYTE6)
-        OUT     (C),A
-	CALL	RECOVER
-        LD      A,(BYTE7)
-        OUT     (C),A
-	CALL	RECOVER
-	LD      A,(BYTE8)
-        OUT     (C),A
-	CALL	RECOVER
+	IN	A,(C)			; prime autoincrement
+	LD HL,SCRLBUF
+	LD DE,24*40
+N8V_VDASCR2:
+	IN	A,(C)
+	LD (HL),A
+	INC HL
+	DEC DE
+	LD A,D
+	OR E
+	JR NZ,N8V_VDASCR2
+	
+	; COPY UP 23 LINES
+	LD HL,0
+	CALL VDP_WRVRAM
+	LD HL,SCRLBUF+40
+	LD DE,(24*40)-40
+	LD C,DATAP
+	OUT (C),A
+N8V_VDASCR3:
+	LD A,(HL)
+	OUT (C),A
+	INC HL
+	DEC DE
+	LD A,D
+	OR E
+	JR NZ,N8V_VDASCR3
+
+	; BLANK LAST 40
+	LD DE,40
+N8V_VDASCR4:
+	LD A,' '
+	OUT (C),A
+	DEC DE
+	LD A,D
+	OR E
+	JR NZ,N8V_VDASCR4
+	
+	XOR	A
+	RET
 
-        DEC	DE
-	LD	A,D
-	OR	E
-        JR      NZ,VDP_LOAD2LOOP
-        RET
+SCRLBUF	.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+		.db 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
 
 ;-------------------------------------------------
 
-
-
-
-
-VDP_SINE:
-
-	; N8-2312 TMS9918 Text Mode Init Done!
-	LD	HL,0
-	CALL	VDP_WRVRAM
-        LD      HL,VDP_HELLO
-        LD      DE,39
-        LD      C,DATAP
-HELLO_LOOP:
-        LD      A,(HL)
-        OUT     (C),A
-        INC     HL
-        DEC     DE
-        LD      A,D
-        OR      E
-        JR      NZ,HELLO_LOOP
-
-	; N8VEM HBIOS v2.2 B3
-	LD	HL,40+40+40+40+3
-	CALL	VDP_WRVRAM
-	LD	HL,STR_BANNER
-	LD	C,DATAP
-	LD	DE,20
-BAN_LOOP:
-	LD	A,(HL)
-	CP	'('
-	JP	Z,BAN_DONE
-	OUT	(C),A
-	INC	HL
-	DEC	DE
-	LD	A,D
-	OR	E
-	JR	NZ,BAN_LOOP
-BAN_DONE:
-
-
-	; (rOMwbw-DOUG-121113t0113) <BLANK>
-	LD	HL,40+40+40+40+40+3
-	CALL	VDP_WRVRAM
-	;
-	LD	HL,STR_BANNER + 20
-	LD	C,DATAP
-	;
-	LD	DE,27
-BAN_LOOP2:
-	LD	A,(HL)
-	CP	' '
-	JP	Z,BAN_DONE2
-	OUT	(C),A
-	INC	HL
-	DEC	DE
-	LD	A,D
-	OR	E
-	JR	NZ,BAN_LOOP2
-	LD	A,'|'
-	OUT	(C),A
-	CALL	RECOVER
-BAN_DONE2:
-
-	; n8 z180 sbc, floppy (autosize), ppide..
-	PUSH	HL
-	LD	HL,40+40+40+40+40+40+3
-	CALL	VDP_WRVRAM
-	POP	HL
-
-	LD	C,DATAP
-	LD	DE,60
-BAN_LOOP3:
-	LD	A,(HL)
-	CP	'$'
-	JP	Z,BAN_DONE3
-	OUT	(C),A
-	INC	HL
-	DEC	DE
-	LD	A,D
-	OR	E
-	JP	NZ,BAN_LOOP3
-BAN_DONE3:
-
-        RET
-
-
-N8V_FILL:
-	; out(CMDP,0);
-	; out(CMDP,64);
-	; d=0;
-	; for(c=0;c<(40*24);c++) {
-	; 	out(DATAP,d);
-	;	d++;
-	;	if(128 == d) d=0;
-	; }
-	RET
-
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+; Video Display Processor Write the VRAM address registers ;
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 VDP_WRVRAM:
 	; HL -> points to ram location
-
-	; vdp_wrvram(o)
-	; {
-	; 	byte1 = o & 255;
-	;	byte2 = (o >> 8) | 0x40;
-	;	out(CMDP,byte1);
-	;	out(CMDP,byte2);
-	; }
-
 	LD	C,CMDP
 	OUT	(C),L
 	CALL	RECOVER
@@ -530,31 +646,21 @@ VDP_WRVRAM:
 	CALL	RECOVER
 	RET
 
-
-N8V_DISPLAY:
-	; vdp_display(line,column,string)
-	; {
-	;	vdp_wrvram(GUTTER+(line*40)+column);
-	;	for(index=0;index<strlen(string);index++) {
-	;		out(DATAP,string[index]);
-	;	}
-	; }	
-	RET
-
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+; Recovery-time delay routine - Conservatively long delay ;
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 RECOVER:
 	PUSH	BC
 	PUSH	DE
 	PUSH	HL
-	POP	HL
-	POP	DE
-	POP	BC
+	POP		HL
+	POP		DE
+	POP		BC
 	RET
 
-;
-;__________________________________________________________________________________________________
-; LOCAL DRIVER DATA
-;__________________________________________________________________________________________________
-;
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+; Video Display Processor Local Driver Data ;
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
 VDP_DEVUNIT	.DB	0
 VDP_ROW		.DB	0	; row number 0-23
@@ -577,3 +683,13 @@ BYTE8           .DB     0
 
 CHARSET:
 #INCLUDE "n8chars.inc"
+
+row_offs	.dw	40* 0,40* 1,40* 2,40* 3,40* 4,40* 5,40* 6,40* 7
+			.dw 40* 8,40* 9,40*10,40*11,40*12,40*13,40*14,40*15
+			.dw 40*16,40*17,40*18,40*19,40*20,40*21,40*22,40*23
+;
+
+
+;;;;;;;;;;;;;;;;;
+; eof - n8v.asm ;
+;;;;;;;;;;;;;;;;;