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add PCJr-compatible dos memory layout

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Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@2400
This commit is contained in:
Sebastian Strohhäcker 2005-12-03 10:43:22 +00:00
parent ed1cadea92
commit de579c6a89
4 changed files with 54 additions and 10 deletions
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17
src/dos/dos_execute.cpp
View file

@ -16,7 +16,7 @@
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
/* $Id: dos_execute.cpp,v 1.51 2005-10-17 20:17:08 c2woody Exp $ */
/* $Id: dos_execute.cpp,v 1.52 2005-12-03 10:43:22 c2woody Exp $ */
#include <string.h>
#include <ctype.h>
@ -274,6 +274,7 @@ bool DOS_Execute(char * name,PhysPt block_pt,Bit8u flags) {
if (imagesize+headersize<512) imagesize = 512-headersize;
}
}
Bit8u * loadbuf=(Bit8u *)new Bit8u[0x10000];
if (flags!=OVERLAY) {
/* Create an environment block */
envseg=block.exec.envseg;
@ -285,6 +286,14 @@ bool DOS_Execute(char * name,PhysPt block_pt,Bit8u flags) {
Bit16u minsize,maxsize;Bit16u maxfree=0xffff;DOS_AllocateMemory(&pspseg,&maxfree);
if (iscom) {
minsize=0x1000;maxsize=0xffff;
if (machine==MCH_PCJR) {
/* try to load file into memory below 96k */
pos=0;DOS_SeekFile(fhandle,&pos,DOS_SEEK_SET);
Bit16u dataread=0x1800;
DOS_ReadFile(fhandle,loadbuf,&dataread);
if (dataread<0x1800) maxsize=dataread;
if (minsize>maxsize) minsize=maxsize;
}
} else { /* Exe size calculated from header */
minsize=long2para(imagesize+(head.minmemory<<4)+256);
if (head.maxmemory!=0) maxsize=long2para(imagesize+(head.maxmemory<<4)+256);
@ -298,6 +307,11 @@ bool DOS_Execute(char * name,PhysPt block_pt,Bit8u flags) {
if (maxfree<maxsize) memsize=maxfree;
else memsize=maxsize;
if (!DOS_AllocateMemory(&pspseg,&memsize)) E_Exit("DOS:Exec error in memory");
if (iscom && (machine==MCH_PCJR) && (pspseg<0x2000)) {
maxsize=0xffff;
/* resize to full extent of memory block */
DOS_ResizeMemory(pspseg,&maxsize);
}
loadseg=pspseg+16;
if (!iscom) {
/* Check if requested to load program into upper part of allocated memory */
@ -306,7 +320,6 @@ bool DOS_Execute(char * name,PhysPt block_pt,Bit8u flags) {
}
} else loadseg=block.overlay.loadseg;
/* Load the executable */
Bit8u * loadbuf=(Bit8u *)new Bit8u[0x10000];
loadaddress=PhysMake(loadseg,0);
if (iscom) { /* COM Load 64k - 256 bytes max */

31
src/dos/dos_memory.cpp
View file

@ -252,7 +252,7 @@ bool DOS_FreeMemory(Bit16u segment) {
void DOS_BuildUMBChain(const char* use_umbs,bool ems_active) {
if (strcmp(use_umbs,"false")!=0) {
if ((strcmp(use_umbs,"false")!=0) && (machine!=MCH_TANDY)) {
Bit16u first_umb_seg=0xca00;
Bit16u first_umb_size=0x600;
@ -365,7 +365,7 @@ static CALLBACK_HandlerObject callbackhandler;
void DOS_SetupMemory(void) {
// Create a dummy device MCB with PSPSeg=0x0008
DOS_MCB mcb_devicedummy((Bit16u)DOS_MEM_START);
mcb_devicedummy.SetPSPSeg(0x0008); // Devices
mcb_devicedummy.SetPSPSeg(MCB_DOS); // Devices
mcb_devicedummy.SetSize(1);
mcb_devicedummy.SetType(0x4d); // More blocks will follow
// mcb_devicedummy.SetFileName("SD ");
@ -388,10 +388,31 @@ void DOS_SetupMemory(void) {
DOS_MCB mcb((Bit16u)DOS_MEM_START+2);
mcb.SetPSPSeg(MCB_FREE); //Free
if (machine==MCH_TANDY) {
mcb.SetSize(0x97FE - DOS_MEM_START - 2);
} else mcb.SetSize(0x9FFE - DOS_MEM_START - 2);
mcb.SetType(0x5a); //Last Block
if (machine==MCH_TANDY) {
/* memory up to 608k available, the rest (to 640k) is used by
the tandy graphics system's variable mapping of 0xb800 */
mcb.SetSize(0x97FE - DOS_MEM_START - 2);
} else if (machine==MCH_PCJR) {
/* memory from 128k to 640k is available */
mcb_devicedummy.SetPt((Bit16u)0x2000);
mcb_devicedummy.SetPSPSeg(MCB_FREE);
mcb_devicedummy.SetSize(0x9FFE - 0x2000);
mcb_devicedummy.SetType(0x5a);
/* exclude PCJr graphics region */
mcb_devicedummy.SetPt((Bit16u)0x17ff);
mcb_devicedummy.SetPSPSeg(MCB_DOS);
mcb_devicedummy.SetSize(0x800);
mcb_devicedummy.SetType(0x4d);
/* memory below 96k */
mcb.SetSize(0x1800 - DOS_MEM_START - 4);
mcb.SetType(0x4d);
} else {
/* complete memory up to 640k available */
mcb.SetSize(0x9FFE - DOS_MEM_START - 2);
}
dos.firstMCB=DOS_MEM_START;
dos_infoblock.SetFirstMCB(DOS_MEM_START);