From ad7695d707e51b98f16fd788f83cc243731ff86f Mon Sep 17 00:00:00 2001
From: Ralf Grillenberger <h-a-l-9000@users.sourceforge.net>
Date: Mon, 28 Jun 2010 12:16:15 +0000
Subject: [PATCH] Fix regression in Spacewar with Hercules video. Thanks
 ripsaw8080 for reporting.

Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@3617
---
 src/hardware/vga_other.cpp | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/hardware/vga_other.cpp b/src/hardware/vga_other.cpp
index 710b6c07..7fd18293 100644
--- a/src/hardware/vga_other.cpp
+++ b/src/hardware/vga_other.cpp
@@ -516,7 +516,12 @@ static void write_hercules(Bitu port,Bitu val,Bitu /*iolen*/) {
 		break;
 		}
 	case 0x3bf:
-		vga.herc.enable_bits=(Bit8u)val;
+		if ( vga.herc.enable_bits ^ val) {
+			vga.herc.enable_bits=val;
+			// Bit 1 enables the upper 32k of video memory,
+			// so update the handlers
+			VGA_SetupHandlers();
+		}
 		break;
 	}
 }