Re: Is it Possible to install a 1996, 3.5", 3 disk Generic CAD Program into DOSBox?

Posted on 2023-03-18, 21:56

by

by jmarsh

in DOSBox Games/Apps

in DOSBox Games/Apps

the emulated FPU in DOSBox cannot pass the Intel MCP test program, so I would not use it for anything important. Neither can native machines past Pentium 2, due to changes in the floating point unit's accuracy. It doesn't mean they are less accurate, they simply don't give the exact results that …

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Re: SD-IDE or CF-IDE adapters - Is there any recommended model/make?

Posted on 2023-03-15, 20:47

by

by jmarsh

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

CABLE SELECT is either already connected to ground or floating (assuming the CF adapter is connected to a CS compatible cable and not the controller's pins directly), grounding it isn't going to matter.

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Re: Breakpoint on DOS Program Start

Posted on 2023-03-05, 00:02

by

by jmarsh

in PC Emulation

in PC Emulation

Write your own .com that calls int21.4b with al=1 to load the program to be debugged, then jump to the new ip with the trap flag set (or some other method to notify your emulator to break).

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Re: Everytime i write a command, dosbox adds a point "."

Posted on 2023-02-28, 19:44

by

by jmarsh

in DOSBox General

in DOSBox General

Which operating system/version of DOSBox? Sounds suspiciously like a mobile issue...

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Re: My PC took fire

Posted on 2023-02-23, 21:34

by

by jmarsh

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Maybe cheap and nasty metal used for the pins in the plug, that "splintered" and created a metal whisker when it got plugged into something. Think what happens when you put steel wool on a battery's terminals...

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Re: accidentally set etherlink iii boot rom to C0000, is my card useless now ?

Posted on 2023-02-23, 21:28

by

by jmarsh

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

maxtherabbit wrote on 2023-02-23, 14:32: if you just remove the ROM chip from the socket you should still be able to boot up with the card + a VGA I think Would be interested to hear if this works, or if the card still tries to respond to the memory reads and clobbers the video card's response ( …

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Re: IDE/CF adapter causing screen corruption/missing characters

Posted on 2023-02-23, 11:27

by

by jmarsh

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I wouldn't be surprised if the CF cards would either always output 3.3v on their data pins or if they make it dependant on the input voltage were the voltage regulator connects to. Of course it's dependant on the source voltage, that's how ICs (unless explicitly stated otherwise) work. Which is yet …

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Re: IDE/CF adapter causing screen corruption/missing characters

Posted on 2023-02-22, 22:04

by

by jmarsh

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I don't think the same.: 3.3v is the prefered voltage, hence the regulators. 5v is a legacy voltage, CF cards care "5v tolerant". Devices that are "tolerant" of higher voltages usually only accept them as output, they don't output at those voltages. That is not the case with CompactFlash. The …

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Re: IDE/CF adapter causing screen corruption/missing characters

Posted on 2023-02-22, 20:42

by

by jmarsh

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

CompactFlash can work at both 3.3v and 5v. Neither is "correct." Some IDE adapters have a jumper to make a linear regulator convert 5v to 3.3v for the card's power, but that's pointless since the 5v IDE address/data lines are connected directly to the card's pins.

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Re: IDE/CF adapter causing screen corruption/missing characters

Posted on 2023-02-22, 18:52

by

by jmarsh

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

The problem with the SD adapter sounds like the classic Sintech/FC1307 bug where the adapter freaks out if the IDE interface is reset and it can't find an active FAT16/32 partition in the card's partition table. The instability issue with the CF based cards sounds like they're pulling too much power …

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Re: Several VESA video modes aren't working in DOS Box

Posted on 2023-02-20, 21:54

by

by jmarsh

in DOSBox Development

in DOSBox Development

It's already been explained to you that VBE2.0 made defined modes deprecated and they should not be relied upon. Deal with it or any app you write may break on any real card that defines modes differently from what you expect.

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Re: Several VESA video modes aren't working in DOS Box

Posted on 2023-02-20, 13:32

by

by jmarsh

in DOSBox Development

in DOSBox Development

Ok. But shouldn't DosBox support all the documented modes, just in case there's some game out there that uses them? I thought VESA was supposed to have a mandatory minimum set of modes that needed to be included in a graphics card to be considered VESA compliant. And it would make sense if it was …

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Re: Several VESA video modes aren't working in DOS Box

Posted on 2023-02-20, 07:38

by

by jmarsh

in DOSBox Development

in DOSBox Development

From the very same wikipedia page: Beginning with the VBE 2.0 standard, no new modes will be defined by VESA, and old modes are no longer mandatory. The use of defined modes should be considered deprecated: modern video cards may or may not use these mode numbers (even though most do for backward …

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Re: PicoGUS: Gravis Ultrasound emulator on an ISA card with Raspberry Pi Pico

Posted on 2023-02-18, 17:58

by

by jmarsh

in Marvin \ Sound

in Marvin \ Sound

FreddyV is working on drive emulation in his PicoMEM project. So far it is looking extremely promising: https://forum.vcfed.org/index.php?threads/picomem-project-pi-pico-on-an-isa-board.1241199/ That project also looks like it's 8-bit only, so would have the same limitation/issue. While it's …

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Re: PicoGUS: Gravis Ultrasound emulator on an ISA card with Raspberry Pi Pico

Posted on 2023-02-18, 10:56

by

by jmarsh

in Marvin \ Sound

in Marvin \ Sound

Just in theory... would it be possible to add an sd slot to the SPI lines used for the sample ram (requires finding a pin for the SD CS) in order to add ATAPI IDE emulation? Seems like a logical step since there's already a DAC hooked up for CDDA output... Edit: Actually nevermind... realized that …

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Re: CRT Terminator Digital VGA Feature Card ISA DV1000

Posted on 2023-02-10, 16:37

by

by jmarsh

in Release Announcements

in Release Announcements

While we are visiting this topic, there is also a third demo, Kukoo 2 , which was consciously rejected from being supported. It does palette color changes at each scanline to get more than 256 colors in a single frame. Supporting that demo would require actively delaying the video signal in order …

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Re: Dosbox scaling for resizing a SVGA 640x480x256 game

Posted on 2023-02-10, 15:20

by

by jmarsh

in DOSBox General

in DOSBox General

Show exactly how you're adding " forced" to the scaler name?

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Re: Dosbox scaling for resizing a SVGA 640x480x256 game

Posted on 2023-02-09, 05:53

by

by jmarsh

in DOSBox General

in DOSBox General

output=openglnb if you don't want blended pixels.

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Re: Mount/imgmount after boot from hardfile.

Posted on 2023-02-07, 14:11

by

by jmarsh

in DOSBox General

in DOSBox General

No, that's why the wiki says what it does.

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Re: Dosbox scaling for resizing a SVGA 640x480x256 game

Posted on 2023-02-07, 14:10

by

by jmarsh

in DOSBox General

in DOSBox General

By default scalers are only used on low resolutions, add " forced" after the name for use with SVGA resolutions and up. A better option might be to use a different output mode (opengl or directdraw) that uses gpu scaling.

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