From ca58b4cf619dc4a7d25fcff71aff471c7c93add2 Mon Sep 17 00:00:00 2001
From: Sjoerd van der Berg <harekiet@users.sourceforge.net>
Date: Sat, 17 Jan 2004 09:56:33 +0000
Subject: [PATCH] Fix up hercules graphics mode a bit

Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@1593
---
 src/hardware/vga_draw.cpp   |  7 +++----
 src/hardware/vga_memory.cpp |  7 ++++++-
 src/hardware/vga_misc.cpp   | 16 +++++++++-------
 3 files changed, 18 insertions(+), 12 deletions(-)

diff --git a/src/hardware/vga_draw.cpp b/src/hardware/vga_draw.cpp
index 63cc6773..0843f384 100644
--- a/src/hardware/vga_draw.cpp
+++ b/src/hardware/vga_draw.cpp
@@ -28,7 +28,7 @@
 #define FIXED_CGA_SIZED	1
 
 static void VGA_HERC_Draw(Bit8u * bitdata,Bitu pitch) {
-	Bit8u * reader=&vga.mem.linear[(vga.herc.mode_control & 0x80) ? 8*1024 : 0];
+	Bit8u * reader=&vga.mem.linear[0];
 	for (Bitu y=0;y<vga.draw.height;y++) {
 		Bit8u * tempread=reader+((y & 3) * 8 * 1024);
 		Bit8u * draw=bitdata;
@@ -250,7 +250,6 @@ static void VGA_BlankTimer() {
 	vga.config.retrace=true;
 }
 
-
 void VGA_DrawHandler(RENDER_Part_Handler part_handler) {
 	Bit8u * buf,* bufsplit;
 	/* Draw the current frame */
@@ -421,9 +420,9 @@ void VGA_SetupDrawing(void) {
 	case M_HERC:
 		vga.draw.double_height=false;		//Hack if there's a runtime switch
 		width*=9;
-		height=384;
+		height=348;
 		pitch=width;
-		aspect_ratio=1.0;
+		aspect_ratio=1.5;
 		break;
 	case M_TANDY16:
 		width<<=3;
diff --git a/src/hardware/vga_memory.cpp b/src/hardware/vga_memory.cpp
index e770c919..45d720f2 100644
--- a/src/hardware/vga_memory.cpp
+++ b/src/hardware/vga_memory.cpp
@@ -297,9 +297,12 @@ void VGA_SetupHandlers(void) {
 	case M_CGA16:
 	case M_CGA4:
 	case M_CGA2:
-	case M_HERC:
 		range_handler=&vgaph.hmap;
 		break;
+	case M_HERC:
+		range_handler=&vgaph.hmap;
+		if (vga.herc.mode_control&0x80) goto range_b800;
+		else goto range_b000;
 	default:
 		LOG_MSG("Unhandled vga mode %X",vga.mode);
 	}
@@ -311,12 +314,14 @@ void VGA_SetupHandlers(void) {
 		MEM_SetPageHandler(VGA_PAGE_B0,16,&vgaph.hram);
 		break;
 	case 2:
+range_b000:
 		vgapages.map_base=VGA_PAGE_B0;
 		MEM_SetPageHandler(VGA_PAGE_B0,8,range_handler);
 		MEM_SetPageHandler(VGA_PAGE_A0,16,&vgaph.hram);
 		MEM_SetPageHandler(VGA_PAGE_B8,8,&vgaph.hram);
 		break;
 	case 3:
+range_b800:
 		vgapages.map_base=VGA_PAGE_B8;
 		MEM_SetPageHandler(VGA_PAGE_B8,8,range_handler);
 		MEM_SetPageHandler(VGA_PAGE_A0,16,&vgaph.hram);
diff --git a/src/hardware/vga_misc.cpp b/src/hardware/vga_misc.cpp
index 16b49632..1b4439f5 100644
--- a/src/hardware/vga_misc.cpp
+++ b/src/hardware/vga_misc.cpp
@@ -207,13 +207,15 @@ static Bit8u read_p3cc(Bit32u port) {
 
 
 static void write_hercules(Bit32u port,Bit8u val) {
+	Bit8u mask;
 	switch (port) {
 	case 0x3b8:
+		mask=0xff-0x80-0x2;;
 		if (vga.herc.enable_bits & 1) {
+			mask|=0x2;
 			if (vga.mode != M_HERC || vga.mode != M_TEXT2) {
-				VGA_ATTR_SetPalette(1,0x0f);
-				/* Hack around like it looks we are in 0xb000 segment */
-				vga.gfx.miscellaneous=(vga.gfx.miscellaneous & ~0x0c)|0x0a;
+				VGA_ATTR_SetPalette(1,0x07);
+				/* Force 0x3b4/5 registers */
 				if (vga.misc_output & 1) write_p3c2(0,vga.misc_output & ~1);
 			}
 			if (val & 0x2) {
@@ -223,9 +225,10 @@ static void write_hercules(Bit32u port,Bit8u val) {
 			}
 		}
 		if (vga.herc.enable_bits & 0x2) {
-			LOG_MSG("Herc page %d",val >> 7);
+			mask|=0x80;
+			VGA_SetupHandlers();
 		}
-		vga.herc.mode_control=val;
+		vga.herc.mode_control=(vga.herc.mode_control & ~mask) | (val&mask);
 		break;
 	case 0x3bf:
 		vga.herc.enable_bits=val;
@@ -248,8 +251,6 @@ static Bit8u read_hercules(Bit32u port) {
 
 
 void VGA_SetupMisc(void) {
-//	if (machine==MCH_HERC) EnableHercules();
-
 	vga.herc.enable_bits=0;
 	IO_RegisterWriteHandler(0x3d8,write_p3d8,"VGA Feature Control Register");
 	IO_RegisterWriteHandler(0x3d9,write_p3d9,"CGA Color Select Register");
@@ -259,6 +260,7 @@ void VGA_SetupMisc(void) {
 	IO_RegisterReadHandler(0x3cc,read_p3cc,"VGA Misc Output");
 
 	if (machine==MCH_HERC || machine==MCH_AUTO) {
+		vga.herc.mode_control=0x8;
 		IO_RegisterWriteHandler(0x3b8,write_hercules,"Hercules");
 		IO_RegisterWriteHandler(0x3bf,write_hercules,"Hercules");
 	}