Re: 64-bit dynamic_x86 (patch)

Posted on 2019-06-26, 07:10

by

by jmarsh

in DOSBox Development

in DOSBox Development

You need to test games that use self-modifying code, which causes hostmem to get accessed directly by the emitted code (for frequently modified instructions). Games using the Build engine are the most common example so if RR didn't trigger it you likely won't have an issue. There's not much point …

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Re: 64-bit dynamic_x86 (patch)

Posted on 2019-06-25, 07:33

by

by jmarsh

in DOSBox Development

in DOSBox Development

AFAIK the difference between 1 and 2 is that memory returned by brk() will be randomized at the higher level. Data segments can't be randomized as the text segments contain fixed RIP-relative offsets to them.

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Re: 64-bit dynamic_x86 (patch)

Posted on 2019-06-25, 03:12

by

by jmarsh

in DOSBox Development

in DOSBox Development

I know about the potential randomness of libc memory allocation. But to be frank, I never understand that why it occurred every time with specific families of Intel CPUs, but not even once on AMD CPUs. Possibly it's related to the read/write fsbase/gsbase instructions being available but that seem …

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Re: 64-bit dynamic_x86 (patch)

Posted on 2019-06-25, 02:24

by

by jmarsh

in DOSBox Development

in DOSBox Development

It has nothing to do with the CPU type, but how your libc allocates memory. Specifically how two consecutive allocations can return pointers that are at completely opposite ends of the virtual address range instead of being close to each other.

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Re: WavePi: Use Raspberry pi as a AIO MIDI synth

Posted on 2019-06-23, 01:26

by

by jmarsh

in Marvin \ Sound

in Marvin \ Sound

Diodes will not do anything useful either except drop voltage, and such small diodes are gonna drop a whole volt under load while not helping much at all with the load sharing problem. Diodes on the output stage prevent one convertor from feeding back into another (that may have a slightly lower …

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Re: WavePi: Use Raspberry pi as a AIO MIDI synth

Posted on 2019-06-22, 13:42

by

by jmarsh

in Marvin \ Sound

in Marvin \ Sound

Linear convertors like the 7805 don't really like being connected in parallel... but it sounds like you already figured that out. You *can* tie them together with diodes, but then you need another diode on their earth to compensate for the voltage loss.

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Re: A soundcard (Crystal CX4235-XQ3) with a DC power adapter plug?

Posted on 2019-06-21, 06:46

by

by jmarsh

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

It was a power output...

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Re: 64-bit dynamic_x86 (patch)

Posted on 2019-06-20, 10:50

by

by jmarsh

in DOSBox Development

in DOSBox Development

Unless something works with core=normal, it's out of scope for dynamic cores.

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Re: 64-bit dynamic_x86 (patch)

Posted on 2019-06-20, 03:58

by

by jmarsh

in DOSBox Development

in DOSBox Development

Patch updated to optimize gen_call_function().

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64-bit dynamic_x86 (patch)

Posted on 2019-06-20, 01:44

by

by jmarsh

in DOSBox Development

in DOSBox Development

Since the current 64-bit builds of DOSBox only support the slower dynrec core I decided it was time to port the dynamic_x86 core. Results look good; a huge speed boost over current 64-bit builds and around 10-20% improvement over 32-bit dyn_x86. Just in time for Apple and Ubuntu to drop 32-bit …

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Re: Weird Cooling Problem with Q9550 on P5K SE

Posted on 2019-06-08, 05:10

by

by jmarsh

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Everything looks pretty normal. As someone said earlier, it's basically two core2duos stuck together so the core temps will be paired. One pair of cores will always be hotter than the other. Temps in the BIOS will likely be higher than expected because speedstep won't be active (to slow the CPU when …

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Re: PCMCIA USB 1.0/2.0 usable in DOS?

Posted on 2019-06-07, 16:05

by

by jmarsh

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Get a PCMCIA compactflash adaptor.

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Re: DOSBox Feature Request Thread

Posted on 2019-06-07, 01:37

by

by jmarsh

in DOSBox General

in DOSBox General

Those aren't DOS commands, they're programs. Commands are executed by the command interpreter (e.g. command.com).

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Re: Cannot enter BIOS setup on my Pentium 60

Posted on 2019-06-06, 17:59

by

by jmarsh

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Jesus, that poor cpu is literally battle-scarred.

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Re: DOSBox Feature Request Thread

Posted on 2019-06-06, 07:26

by

by jmarsh

in DOSBox General

in DOSBox General

If you want real DOS commands, just run real DOS in DOSBox.

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Re: DOSBox Feature Request Thread

Posted on 2019-06-06, 03:09

by

by jmarsh

in DOSBox General

in DOSBox General

If you want dates preserved you will have to mount disk images instead of directories, knowing the command details won't be enough.

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Re: Diablo Hellfire high res

Posted on 2019-06-05, 15:02

by

by jmarsh

in Release Announcements

in Release Announcements

It's not "high res", they just used a directdraw wrapper that stretches the original 640x480 to whatever resolution you tell it to.

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Re: Vanilla / Dos Doom in 3 screen mode. I finally did it!

Posted on 2019-06-04, 10:54

by

by jmarsh

in Marvin \ Software

in Marvin \ Software

You're telling it to start a 3 player network game so it's waiting until there are 3 players.

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Re: 486 Dallas battery coin adapter mod ?

Posted on 2019-06-01, 02:38

by

by jmarsh

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

This is what I ended up doing for another one of my 486 boards, but it had the corroded barrel battery. You can do this same setup for the Dallas battery, you just need to cut into the battery and solder onto the + & - leads inside. No you can't. Barrel batteries get recharged when the PC is on, …

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Re: CF adaptor issues.

Posted on 2019-05-29, 02:24

by

by jmarsh

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

A lot of cheap CF adaptors are designed to act as both master and slave, but they only have one card slot installed and leave the other unpopulated. The jumper merely selects which slot is master.

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