From ef5e7f519ef8d8f044bebe231746cbeaf0035326 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sebastian=20Strohh=C3=A4cker?=
 <c2woody@users.sourceforge.net>
Date: Mon, 19 Dec 2005 20:39:51 +0000
Subject: [PATCH] fake a 128k-PCJr when com files are loaded low (dos memory
 only)

Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@2417
---
 src/dos/dos_execute.cpp  | 10 +++++++++-
 src/dos/dos_memory.cpp   |  9 ++++++++-
 src/dos/dos_programs.cpp | 12 +++++-------
 3 files changed, 22 insertions(+), 9 deletions(-)

diff --git a/src/dos/dos_execute.cpp b/src/dos/dos_execute.cpp
index 29ccb928..966aded7 100644
--- a/src/dos/dos_execute.cpp
+++ b/src/dos/dos_execute.cpp
@@ -16,7 +16,7 @@
  *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
 
-/* $Id: dos_execute.cpp,v 1.52 2005-12-03 10:43:22 c2woody Exp $ */
+/* $Id: dos_execute.cpp,v 1.53 2005-12-19 20:39:51 c2woody Exp $ */
 
 #include <string.h>
 #include <ctype.h>
@@ -311,6 +311,14 @@ bool DOS_Execute(char * name,PhysPt block_pt,Bit8u flags) {
 			maxsize=0xffff;
 			/* resize to full extent of memory block */
 			DOS_ResizeMemory(pspseg,&maxsize);
+			/* now try to lock out memory above segment 0x2000 */
+			if ((real_readb(0x2000,0)==0x5a) && (real_readw(0x2000,1)==0) && (real_readw(0x2000,3)==0x7ffe)) {
+				/* MCB after PCJr graphics memory region is still free */
+				if (pspseg+maxsize==0x17ff) {
+					DOS_MCB cmcb((Bit16u)(pspseg-1));
+					cmcb.SetType(0x5a);		// last block
+				}
+			}
 		}
 		loadseg=pspseg+16;
 		if (!iscom) {
diff --git a/src/dos/dos_memory.cpp b/src/dos/dos_memory.cpp
index 19bf2d1a..dbdd7063 100644
--- a/src/dos/dos_memory.cpp
+++ b/src/dos/dos_memory.cpp
@@ -49,7 +49,14 @@ void DOS_FreeProcessMemory(Bit16u pspseg) {
 		if (mcb.GetPSPSeg()==pspseg) {
 			mcb.SetPSPSeg(MCB_FREE);
 		}
-		if (mcb.GetType()==0x5a) break;
+		if (mcb.GetType()==0x5a) {
+			/* check if currently last block reaches up to the PCJr graphics memory */
+			if ((machine==MCH_PCJR) && (mcb_segment+mcb.GetSize()==0x17fe) &&
+                (real_readb(0x17ff,0)==0x4d) && (real_readw(0x17ff,1)==8)) {
+				/* re-enable the memory past segment 0x2000 */
+				mcb.SetType(0x4d);
+			} else break;
+		}
 		mcb_segment+=mcb.GetSize()+1;
 		mcb.SetPt(mcb_segment);
 	}
diff --git a/src/dos/dos_programs.cpp b/src/dos/dos_programs.cpp
index 423ace13..3432341d 100644
--- a/src/dos/dos_programs.cpp
+++ b/src/dos/dos_programs.cpp
@@ -16,7 +16,7 @@
  *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
 
-/* $Id: dos_programs.cpp,v 1.48 2005-12-04 21:17:28 c2woody Exp $ */
+/* $Id: dos_programs.cpp,v 1.49 2005-12-19 20:39:51 c2woody Exp $ */
 
 #include <stdlib.h>
 #include <string.h>
@@ -287,7 +287,9 @@ public:
 
 		Bit16u seg,blocks;blocks=0xffff;
 		DOS_AllocateMemory(&seg,&blocks);
-		WriteOut(MSG_Get("PROGRAM_MEM_CONVEN"),blocks*16/1024);
+		if ((machine==MCH_PCJR) && (real_readb(0x2000,0)==0x5a) && (real_readw(0x2000,1)==0) && (real_readw(0x2000,3)==0x7ffe)) {
+			WriteOut(MSG_Get("PROGRAM_MEM_CONVEN"),0x7ffe*16/1024);
+		} else WriteOut(MSG_Get("PROGRAM_MEM_CONVEN"),blocks*16/1024);
 
 		if (umb_start!=0xffff) {
 			DOS_LinkUMBsToMemChain(1);
@@ -451,11 +453,7 @@ public:
 				fclose(usefile);
 
 				/* write cartridge data into ROM */
-				Bit16u romseg=0xe000;
-				if ((rombuf[7]==0x42) && (rombuf[8]==0x41) && (rombuf[9]==0x53) && (rombuf[10]==0x49)) {
-					/* BASIC rom, doesn't work though */
-					romseg=0xf600;
-				}
+				Bit16u romseg=host_readw(&bootarea.rawdata[0x1ce]);
 				for(i=0;i<rombytesize;i++) phys_writeb((romseg<<4)+i,rombuf[i]);
 
 				/* run cartridge setup */