Re: Identifying strange connector

Posted on 2020-01-18, 10:36

by

by jmarsh

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Kippykip wrote on 2020-01-18, 07:21: Instead what I'm thinking, was there maybe some proprietary breakout extension cable that made a 2xmale USBs, a mic/speaker out or something and literally just forwarded the plugs on the back onto the sidepanel? I mean, that is literally what is stamped on the …

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Re: What methods of A20 line enabling does DosBox support?

Posted on 2020-01-18, 01:45

by

by jmarsh

in DOSBox Development

in DOSBox Development

It's a standard AT bios function. Keep in mind the bios isn't magic, it just contains a bunch of x86 subroutines. The function doesn't do anything that your program couldn't implement directly, and will trigger the same exceptions if the CPU is already running protected.

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Re: What methods of A20 line enabling does DosBox support?

Posted on 2020-01-17, 06:51

by

by jmarsh

in DOSBox Development

in DOSBox Development

Int 15/AH=89h The description is incorrect with regards to execution continuing at the next instruction after the interrupt, instead the new eip is loaded from cx.

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Re: Video and audio stuttering in fullscreen under manual config in Windows 10

Posted on 2020-01-16, 21:33

by

by jmarsh

in DOSBox General

in DOSBox General

Use output=openglnb.

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Re: What methods of A20 line enabling does DosBox support?

Posted on 2020-01-15, 01:24

by

by jmarsh

in DOSBox Development

in DOSBox Development

It supports it via the keyboard controller and port 92, it doesn't support int15 function 24 but will enable A20 during int 15 function 89 (switch to protected mode).

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Re: CT6960 DVI Port not working

Posted on 2020-01-15, 01:04

by

by jmarsh

in Marvin \ Video

in Marvin \ Video

Are you sure your DVI cable works?

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Re: Problem with old ide hard drive. (wdc ac2700)

Posted on 2020-01-13, 20:07

by

by jmarsh

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Probably has some sort of disk overlay software on it.

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Re: 2.5" parallel hard disk input voltage?

Posted on 2020-01-13, 01:43

by

by jmarsh

in Milliways

in Milliways

It's not an input setting, but will be for controlling the voltage on the IDE side. 3.3V can be used (most of the time) when a compact flash card is connected. A lot of PATA<->CF adapters only support higher PIO and DMA modes when 3.3V is selected but no idea if it would affect this adapter.

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Re: Parameters based on executable name

Posted on 2020-01-13, 00:57

by

by jmarsh

in DOSBox General

in DOSBox General

The combination of output=surface and fullresolution=original makes perfect sense if you think about it; output modes other than surface aren't always available and using a larger resolution with a mode that can't scale is just going to put a postage stamp sized image in the middle of the screen.

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Re: VIDEO Patch for pixel-perfect scaling (SDL1)

Posted on 2020-01-09, 23:24

by

by jmarsh

in DOSBox Patches

in DOSBox Patches

I still see its usefulness, though: performing "pp upscaling + linear downscaling" should in theory give better results than the "linear upscaling" that the standard opengl output implements Regular DOSBox can already do the same thing using "scaler=normal?x forced" to upscale beyond the output …

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Re: Why don’t PC parts work in a Mac ?

Posted on 2020-01-09, 16:12

by

by jmarsh

in Milliways

in Milliways

Also keep in mind on most mobile platforms CPU performance is limited due to thermal throttling. They all do it, the only variant is how often/for how long. It's a different story in a desktop environment where a cooler can be used.

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Re: Why don’t PC parts work in a Mac ?

Posted on 2020-01-09, 15:00

by

by jmarsh

in Milliways

in Milliways

appiah4 wrote on 2020-01-09, 14:48: Faster at doing what? Rendering videos? They fly faster through the air when you throw them (up to a point; the macbook's mass gives them advantage when combined with gravity).

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Re: VIDEO Patch for pixel-perfect scaling (SDL1)

Posted on 2020-01-09, 14:56

by

by jmarsh

in DOSBox Patches

in DOSBox Patches

Then it wouldn't be pixel-perfect...

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Re: Why don’t PC parts work in a Mac ?

Posted on 2020-01-09, 13:44

by

by jmarsh

in Milliways

in Milliways

You might want to go back and compare benchmarks of the PowerPC macs to equivalent Intel systems at the time... They switched to Intel because they're cheap and knew their customers would still pay premium prices for budget hardware.

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Re: DOSBox Sound Blaster emulation (Lowpass Filtering)

Posted on 2020-01-09, 13:35

by

by jmarsh

in DOSBox Development

in DOSBox Development

Yet you're somehow seeing a filtered output from software that does no filtering. The wav capture is exactly what DOSBox outputs, and what it has control over; using any other data and saying it's wrong doesn't really help as who knows what happens once it's handed off to SDL and DOSBox can't do …

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Re: DOSBox Sound Blaster emulation (Lowpass Filtering)

Posted on 2020-01-09, 13:23

by

by jmarsh

in DOSBox Development

in DOSBox Development

But if you're not capturing the output directly (using the wav capture function), you're testing the frequency response of your output device rather than the emulator...

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Re: DOSBox Sound Blaster emulation (Lowpass Filtering)

Posted on 2020-01-09, 13:02

by

by jmarsh

in DOSBox Development

in DOSBox Development

How exactly are you sampling the audio from DOSBox?

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Re: Running Amazon Trail From CD-Rom in Dosbox

Posted on 2020-01-09, 04:57

by

by jmarsh

in DOSBox Games/Apps

in DOSBox Games/Apps

You can mount physical CDs using the "-t cdrom" option.

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Re: $$$ to Convert Lotte's CRT Shader for DosBOX Daum

Posted on 2020-01-09, 04:30

by

by jmarsh

in DOSBox General

in DOSBox General

If anything the dynamic cores are more stable since they handle page faults and other exceptions more gracefully. I just checked with a 12 year old compiler (VS2008), nearly all switch/case statements use a direct table (one lookup) or indirect table (two lookups). If you can give an example of one …

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Re: $$$ to Convert Lotte's CRT Shader for DosBOX Daum

Posted on 2020-01-09, 01:28

by

by jmarsh

in DOSBox General

in DOSBox General

The only way that could possibly be true is if you were talking about the huge switch/case tables for the opcode decoding in the normal/full cores (nothing else comes close to occupying 20% of execution time)... which is why the dynamic cores exist.

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