Re: DOSBox-X branch

Posted on 2020-11-30, 17:29

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by TheGreatCodeholio

in DOSBox Patches

in DOSBox Patches

Try turning down the cycle count. If that helps, you can also try using the cycle count you want and setting a vmemdelay. Try vmemdelay=250 or vmemdelay=400. Neither lowering the cycles or setting vmemdelay has any effect, it flickers just the same even with 500 cycles. So far the only thing that …

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Re: DOSBox-X branch

Posted on 2020-11-30, 15:59

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by TheGreatCodeholio

in DOSBox Patches

in DOSBox Patches

I'm playing Tex Murphy 2 from GOG and the mouse cursor is constantly flickering which drives me mad. I tried different output modes and switching to DOSBox X but the issue prevails, any ideas? Try turning down the cycle count. If that helps, you can also try using the cycle count you want and …

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Re: DOSBox-X branch

Posted on 2020-11-29, 05:04

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by TheGreatCodeholio

in DOSBox Patches

in DOSBox Patches

And yet, nobody describes how the hell you get your own VM map handle whatever-the-hell-it-is for yourself so you can use it. It's designed to map memory from one task (process) into another (possibly different) task. The vm_map_t arguments refer to the source and target tasks. We want the source …

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Re: DOSBox-X branch

Posted on 2020-11-29, 04:29

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by TheGreatCodeholio

in DOSBox Patches

in DOSBox Patches

ChromeOS solves it another way. https://chromium.googlesource.com/chromiumos/third_party/kernel/+/179b15db55fc3642a8e9f0e97e15cfe8a74a406e Unless I'm overlooking something they are skipping over a much simpler solution: linux has memfd_create to associate an fd with memory, avoiding the shmem/ …

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Re: DOSBox-X branch

Posted on 2020-11-28, 23:49

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by TheGreatCodeholio

in DOSBox Patches

in DOSBox Patches

You can also not mix i686 and x86_64 inside one process. You can on windows. All 32-bit apps get loaded with a 64-bit code segment accessible to them, for communicating with the kernel (it's how WoW64 works). Since the segment value is hardcoded and x86 has unprivileged instructions to get a …

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Re: DOSBox-X branch

Posted on 2020-11-28, 22:18

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by TheGreatCodeholio

in DOSBox Patches

in DOSBox Patches

I already modified SDL1.2 in-tree to do almost exactly that for Big Sur to fix the lack of audio. It took a bit of browsing around Apple's developer site, but I figured it out in about half an hour.

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Re: DOSBox-X branch

Posted on 2020-11-28, 16:53

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by TheGreatCodeholio

in DOSBox Patches

in DOSBox Patches

This typecast is optimized out by VS2019's compiler in Release builds, causing only the low 32 bits to be written in any case and a crash when executing the dynamically generated code. DOSBox-X fixes the issue by explicitly masking the pointer by 0xFFFFFFFF for that test instead of relying on …

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Re: DOSBox-X branch

Posted on 2020-11-28, 16:52

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by TheGreatCodeholio

in DOSBox Patches

in DOSBox Patches

This typecast is optimized out by VS2019's compiler in Release builds, causing only the low 32 bits to be written in any case and a crash when executing the dynamically generated code. DOSBox-X fixes the issue by explicitly masking the pointer by 0xFFFFFFFF for that test instead of relying on …

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Re: DOSBox-X branch

Posted on 2020-11-28, 16:48

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by TheGreatCodeholio

in DOSBox Patches

in DOSBox Patches

How do you set up DOSBox-X to show integer scaled window in fullscreen? I can do that easily in original DOSBox but I can't get it to work here. To be perfectly clear what I want to accomplish: I want to scale 320x200 game to 1280x800 so it's pixel perfect with even pixels and I want to display …

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Re: DOSBox-X branch

Posted on 2020-11-28, 09:01

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by TheGreatCodeholio

in DOSBox Patches

in DOSBox Patches

Which compiler do you use for building? If it works on a Pentium 4, it’s likely built for SSE2 (-mfpmath=sse in gcc, might be set by default in recent mingw releases). If you compile with build-mingw-lowend, does it help? That script was originally designed to enable compiling on lower end systems …

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Re: DOSBox-X branch

Posted on 2020-11-28, 08:52

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by TheGreatCodeholio

in DOSBox Patches

in DOSBox Patches

Quick 'thank you' for this, Jon and the other contributors. Neither VirtualBox or VMPlayer would let me install Win98SE in a virtual machine on my Ryzen PC - both were rather faster but both had illegal operation / invalid page fault failures in Regsvr32 (and something else in VirtualBox) so didn't …

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Re: DOSBox-X branch

Posted on 2020-11-28, 08:47

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by TheGreatCodeholio

in DOSBox Patches

in DOSBox Patches

In other news, I sat down with one of the new ARM64-based M1 Apple Macbooks and got DOSBox-X to run on those too. There are some considerations to make for those though, which I thought I'd share so SVN can compile for them too. One is how to compile with SDL2. You're going to need to modify …

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Re: DOSBox-X branch

Posted on 2020-11-28, 08:40

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by TheGreatCodeholio

in DOSBox Patches

in DOSBox Patches

Just a heads up, dynamic x86 core in DOSBox-X has apparently hit a problem with Visual Studio 2019 where x86_64 builds can crash when dynamic core is enabled. There is a double typecast in risc_x64.h that attempts to detect whether the prologue needs to load RBP (a full 64-bit pointer) or EBP (only …

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Re: DOSBox-X branch

Posted on 2020-10-12, 06:30

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by TheGreatCodeholio

in DOSBox Patches

in DOSBox Patches

I am having trouble with the mouse tracking speed in the macOS SDL1 build of DOSBox-X. When I run in my native 'retina' resolution of 5120x2880 in fullscreen mode, the mouse tracking speed is about 50% of what it should be, compared to the same default settings in DOSBox SVN (i.e. I use "100%" …

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Re: DOSBox-X branch

Posted on 2020-08-30, 07:52

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by TheGreatCodeholio

in DOSBox Patches

in DOSBox Patches

Just came in to tell that I compiled the latest DOSBOX-X on my macOS with SDL2 and I had an yellow tint screen when running Windows 3.11. I'm compiling with SDL1 now as we speak to see if the same problem happens there too. With SDL2 version I am also unable to go full screen; instead it just …

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Re: DOSBox-X branch

Posted on 2020-08-01, 20:46

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by TheGreatCodeholio

in DOSBox Patches

in DOSBox Patches

@TheGreatCodeholio: I noticed that litchie from iDOS/DOSPad app for iOS might be open to having a look on DOSBox-X or SVN latest version for updating his iDOS emulator app. Not sure if you'd be interested in working with him to bring the best possible DOS/Win9x emulation to iOS/iPadOS, since now …

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Re: DOSBox-X branch

Posted on 2020-07-26, 18:17

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by TheGreatCodeholio

in DOSBox Patches

in DOSBox Patches

Wow, PC-98 emulation, that's very interesting ! :D It seems that there were a lot of updates to the PC-98 line over the years, how is it managed inside DOSBox-X emulation-wise ? It's handled as a machine type, like anything else in the codebase, and the video mode as it's own enumeration. It is …

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Re: DOSBox-X branch

Posted on 2020-07-26, 06:02

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by TheGreatCodeholio

in DOSBox Patches

in DOSBox Patches

I can't see any evidence of rollback except on a few select instructions (pusha, popa, etc.). Any opcodes that read from memory, perform an operation that modifies flags and then attempt to write a result back to memory have the potential to corrupt the flag state if the memory is mapped as read- …

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Re: DOSBox-X branch

Posted on 2020-07-26, 04:59

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by TheGreatCodeholio

in DOSBox Patches

in DOSBox Patches

It's currently not updating flags at all, and if the write operation faults (e.g. due to read-only memory) the second operand gets updated anyway. xchg also has this problem. Then even if you fix that, there is still the problem that flags aren't rolled back if a fault occurs which affects ALL read …

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Re: DOSBox-X branch

Posted on 2020-07-26, 03:32

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by TheGreatCodeholio

in DOSBox Patches

in DOSBox Patches

Not recently. Is there something that relies on it? Luckily not because it's broken in two different ways, and after fixing those I suspect it will still be broken due to a fundamental flaw in how flags are handled. Hm... https://www.felixcloutier.com/x86/xadd Well, I could go over it to at least …

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