Subtle DOS crashes like a program requesting 64MB of RAM, DOSBox allocating 0MB (65536KB & 0xFFFF == 0KB), and the program then tromping on unrelated memory blocks in extended memory because it thinks it allocated 64MB of RAM. Memory corruption. Crash. I'm willing to assume not every DOS programmer …

I also want to point out I modified src/hardware/memory.cpp to raise the limit to 256MB and I fixed src/ints/xms.cpp to work as I described. I ran DOS games and Windows 3.1 in DOSBox with memsize=256 with no noticeable problems. It could be I fixed precisely what made you cap memory at 64MB in the …

I understand where you're coming from, XMS function 9 takes the memory size from DX (lower 16 bits of EDX). That's correct behavior. What is NOT correct behavior is doing the same to function 0x89 which the Extended Memory Specification states takes the size in EDX (all 32 bits) not DX. DOS programs …

OK I found the 2.28 version of ULTRINIT. I get the same failure. But you can get it to work apparently by setting sbtype=none (disabling Sound Blaster emulation). The GUS and SB IRQ+DMA settings do not overlap, so I don't really understand (yet) why this causes the program to fail. Their setup …

Alright so with the fixed XMS implementation, I changed MAX_MEMORY in src/hardware/memory.cpp to 256 and ran various DOS games I have with memsize=256 (256MB of RAM). No problems that I saw. Some test programs I've written also work just as good as they do under QEMU and VirtualBox with >= 64MB of …

Hey, just found another mistake. In your HIMEM.SYS XMS emulation: The original code was responding to the extended version of ALLOCATE MEMORY (function 0x89) but then chopping off the upper 16 bits of EDX. A program asking for 64MB of RAM would get 0. The whole point of the extended version is to …

No problem here. [gus] gus=true gusrate=44100 gusbase=240 gusirq=5 gusdma=3 ultradir=C:\ULTRASND Are you using normal GUS settings? I know it's possible in DOSBox to use DMA and IRQ assignments the GUS normally can't do...

Fix for extended memcpy (INT 15H AH=0x87): case 0x87: /* Copy extended memory */ { bool enabled = MEM_A20_Enabled(); MEM_A20_Enable(true); Bitu bytes = reg_cx * 2; PhysPt data = SegPhys(es)+reg_si; PhysPt source = (mem_readd(data+0x12) & 0x00FFFFFF) + (mem_readb(data+ 0x17 )<<24); PhysPt dest = (mem …

Alright never mind, I see someone also fixed the pantable: http://dosbox.svn.sourceforge.net/viewvc/dosb … up&pathrev=3727 Still though, anyone interested in the above patches?

I also maintain a private "fork" of DOSBox 0.74 with other changes that might be of interest to you guys: * Numerous fixes to your 8042 keyboard emulation to make it more complete and accurate. Including controller reset, alt scan codes, setting the LEDs, and other arcane features. Hopefully DOS …

I was writing some code just for the hell of it to initialize and play sound through the (fake) GUS provided by DOSBox. The Gravis SDK documents a panning register, but DOSBox doesn't seem to be emulating it at all. Everything is stuck in center, no matter how you modify the panning register. [ …