joncampbell123/dosbox-x
1
0
Fork 0
mirror of https://github.com/joncampbell123/dosbox-x.git synced 2025-10-18 17:32:24 +08:00
Code Issues Packages Projects Releases Wiki Activity

add configuration option where, if machine=cga or machine=hercules, the

Browse Source 
640kb conventional memory area could be extended out to just below
CGA/Hercules video RAM (736KB CGA, 704KB Hercules).
This commit is contained in:
Jonathan Campbell
2014-06-11 01:45:43 -07:00
parent 02940c6778
commit ea1a0300ba
3 changed files with 39 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

13
src/dos/dos_memory.cpp
View File

@@ -19,15 +19,17 @@
#include "dosbox.h"
#include "mem.h"
#include "bios.h"
#include "dos_inc.h"
#include "callback.h"
// uncomment for alloc/free debug messages
#define DEBUG_ALLOC
Bitu UMB_START_SEG = 0x9FFF;
/* FIXME: This should be a variable that reflects the last RAM segment.
* That means 0x9FFF if 640KB or more, or a lesser value if less than 640KB */
#define UMB_START_SEG 0x9fff
//#define UMB_START_SEG 0x9fff
Bit16u first_umb_seg = 0xd000;
Bit16u first_umb_size = 0x2000;
@@ -464,8 +466,13 @@ extern Bit16u DOS_IHSEG;
static CALLBACK_HandlerObject callbackhandler;
void DOS_SetupMemory(void) {
unsigned int seg_limit = MEM_TotalPages()*256;
if (seg_limit > 0xA000) seg_limit = 0xA000;
unsigned int max_conv;
unsigned int seg_limit;
max_conv = mem_readw(BIOS_MEMORY_SIZE) << (10-4);
seg_limit = MEM_TotalPages()*256;
if (seg_limit > max_conv) seg_limit = max_conv;
UMB_START_SEG = max_conv - 1;
/* Let dos claim a few bios interrupts. Makes DOSBox more compatible with
* buggy games, which compare against the interrupt table. (probably a