From 03202f62407e24bd964016dccc06de95df622e3c Mon Sep 17 00:00:00 2001
From: Joshua Wise <joshua@rebirth.joshuawise.com>
Date: Mon, 14 Apr 2008 05:23:34 -0400
Subject: [PATCH 1/1] Framebuffer poking

---
 Framebuffer.v | 14 ++++++++------
 diag.asm      | 28 +++++++++++++++++++++++++++-
 2 files changed, 35 insertions(+), 7 deletions(-)

diff --git a/Framebuffer.v b/Framebuffer.v
index 836f73a..ea0a1a5 100644
--- a/Framebuffer.v
+++ b/Framebuffer.v
@@ -5,7 +5,7 @@
 `define YRES 480
 `define YFPORCH 10
 `define YSYNC 2
-`define YBPORCH 29
+`define YBPORCH 25
 
 `define XOFS ((640-160)/2)
 `define YOFS ((480-144)/2)
@@ -46,8 +46,8 @@ module Framebuffer(
 	
 	reg [2:0] failandloss;
 	assign {vgar, vgag, vgab} =
-		((vgax > `XOFS) && (vgax < (`XOFS + 160)) && (vgay > `YOFS) && (vgay < (`YOFS + 144))) ? {failandloss[2],2'b0,failandloss[1],2'b0,failandloss[0],1'b0} :
-		((vgax < 640) && (vgay < 480)) ? 8'b11100000 :
+		((vgax > `XOFS) && (vgax < (`XOFS + 161)) && (vgay > `YOFS) && (vgay < (`YOFS + 144))) ? {failandloss[2],2'b0,failandloss[1],2'b0,failandloss[0],1'b0} :
+		((vgax < 640) && (vgay < 480)) ? 8'b00000000 :
 		8'b00000000;
 	
 	always @(posedge vgaclk)
@@ -57,16 +57,18 @@ module Framebuffer(
 			if (vgay >= (`YRES + `YFPORCH + `YSYNC + `YBPORCH)) begin
 				vgafb <= 0;
 				vgay <= 0;
-			end else
+				vgax <= 0;
+			end else begin
 				vgay <= vgay + 1;
-			vgax <= 0;
+				vgax <= 0;
+			end
 		end else
 			vgax <= vgax + 1;
 		
 		vgahs <= (vgax >= (`XRES + `XFPORCH)) && (vgax < (`XRES + `XFPORCH + `XSYNC));
 		vgavs <= (vgay >= (`YRES + `YFPORCH)) && (vgay < (`YRES + `YFPORCH + `YSYNC));
 		
-		if ((vgax > `XOFS) && (vgax < (`XOFS + 160)) && (vgay > `YOFS) && (vgay < (`YOFS + 144))) begin
+		if ((vgax > `XOFS) && (vgax < (`XOFS + 161)) && (vgay > `YOFS) && (vgay < (`YOFS + 144))) begin
 			vgafb <= vgafb + 1;
 			failandloss <= fb[vgafb + 1];
 		end
diff --git a/diag.asm b/diag.asm
index e3afaa4..8016400 100644
--- a/diag.asm
+++ b/diag.asm
@@ -24,7 +24,7 @@ main:
 	ld a, $04	;start timer, 4.096KHz
 	ld c, $07
 	ld [c], a
-
+	
 	ld hl, $DF81
 	xor a
 	ld [hli], a
@@ -49,6 +49,27 @@ signon:
 	db $0D,$0A,$1B,"[1mFPGABoy Diagnostic ROM",$1B,"[0m",$0D,$0A,0
 
 vbl:
+	PUSH AF
+	PUSH BC
+	PUSH DE
+	PUSH HL
+	
+	xor a
+	ld c, $0F
+	ld [c], a
+	
+	ld c, $42	; SCY
+	ld a, [c]
+	inc a
+	ld [c], a
+
+	POP HL
+	POP DE
+	POP BC
+	POP AF
+
+	RETI
+
 lcdc:
 	PUSH AF
 	PUSH BC
@@ -72,6 +93,11 @@ tmro:
 	ld c, $0F
 	ld [c], a
 	
+	ld c, $45	; LYC
+	ld a, [c]
+	inc a
+	ld [c], a
+	
 	ld hl, $DF82
 	ld a, [hld]
 	cp 0
-- 
2.43.0