Re: Why was 15kHz support dropped from the VGA standard?

Posted on 2016-09-26, 12:16

by

by Scali

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

SquallStrife wrote: OTOH, EGA 640x350 seems to work, of course the dithering is lost. That's interesting, it seems to perform some kind of vertical resampling to convert it to NTSC-compatible resolution. You lose some resolution, but it's still usable.

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Re: Can't get a 486 to recognize a CD drive?

Posted on 2016-09-26, 11:48

by

by Scali

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

The BIOS doesn't have to detect the CD-ROM drive in order for it to work though (in DOS that is). All you need is: 1) The CD-ROM drive connected to a compatible controller 2) The controller configured to a free IO port (interrupts aren't required, oldskool polling IO is good enough) 3) A compatible …

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Re: Can't get a 486 to recognize a CD drive?

Posted on 2016-09-26, 10:28

by

by Scali

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Some systems can't boot directly from CD-ROM, but need a boot floppy with the CD-ROM driver on it. Have you tried that? I think pretty much no 486 system can boot from CD-ROM. Perhaps some really REALLY late ones are the exception to that rule, but certainly not an ISA-only system, that would be a …

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Re: Why was 15kHz support dropped from the VGA standard?

Posted on 2016-09-26, 10:00

by

by Scali

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

The mobo was apparently designed by IBM. The VGA chip is a WD90C10. Ah, a Paradise SVGA chip. That was a decent performer back in the day as well. And yep, VGA 480 line mode causes the composite monitor to stop working. That would imply that some games using a 320x240 VGA tweakmode would also not …

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Re: Why was 15kHz support dropped from the VGA standard?

Posted on 2016-09-26, 09:19

by

by Scali

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Even if it was a clone CGA card, it would be quite good, colour-wise. I've seen various 'brand' CGA clones that aren't that close to real CGA in composite. In fact, an ATi Small Wonder isn't even close: https://youtu.be/eRVwYCq8X5w But for VGA to have composite at all is nice (well, in the PCI-era …

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Re: Why was 15kHz support dropped from the VGA standard?

Posted on 2016-09-26, 06:50

by

by Scali

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

You mean like how you can see the black spacing when using a CGA monitor? or a 1084 with an Amiga? That's different, because that's caused by using progressive scan on displays designed for interlaced images. There is 'some' black spacing, but it is not an entire scanline or more. They didn't put …

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Re: Why was 15kHz support dropped from the VGA standard?

Posted on 2016-09-25, 23:40

by

by Scali

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

There are CRT monitors that can display 240p signals all the way up to 1080i. Just draw thicker scanlines for low-resolution images. What do you think the scandoubling is for? :) You can't control the thickness of the CRT beam. It is what it is. You can however draw the same scanline multiple times …

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Re: Why was 15kHz support dropped from the VGA standard?

Posted on 2016-09-25, 23:37

by

by Scali

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

And why is this a problem? Are you saying that 240p games displayed on an arcade monitor are ugly? If I boot up Monkey Island on an Amiga connected to a 1084, every horizontal line the video card outputs will be mapped to a single scanline on the monitor, and there will be discernible black lines …

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Re: Why was 15kHz support dropped from the VGA standard?

Posted on 2016-09-25, 23:33

by

by Scali

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Isn't the answer to the original question simply "image quality"? VGA monitors had to be capable of 400 and 480-line modes. That meant they had to have quite a fine raster/small dot pitch. Which means if you were to actually feed such a monitor a 200-line signal, you'd clearly see the black spacing …

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Re: What happened to software rendering?

Posted on 2016-09-25, 20:24

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by Scali

in Windows

in Windows

keropi wrote: I am pretty sure this Q demo also uses the Motorola 56001 DSP chip that is present in all Falcons, this is not just optimized 030 code . Still a great job though Yup... without the DSP, you'd need a bit more oomph. With an 060 at ~60 MHz you can do stuff like this: https://youtu.be/ …

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Re: What happened to software rendering?

Posted on 2016-09-25, 20:13

by

by Scali

in Windows

in Windows

GPU and CPU rendering is pretty much mutually exclusive. That is, the only logical point where you can make a division is with vertex processing. It is (or was rather) somewhat doable to let the CPU do vertex processing, and then push the data to the GPU for the actual triangle rasterization and per …

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Re: I've an idea: Let's get some game development going

Posted on 2016-09-24, 21:51

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by Scali

in Milliways

in Milliways

Just a little point about music : I would suggest SB1.0 compatibility (OPL2/AdLib) instead of OPL3 because many clone cards don't sound as well for SB16 support as they did for SB1.0. In my knowledge SB1.0 compatibility is omnipresent, while OPL3 is less prevalent. OPL3 was introduced with Sound …

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Re: I've an idea: Let's get some game development going

Posted on 2016-09-24, 21:50

by

by Scali

in Milliways

in Milliways

keenmaster486 wrote: OK, that sounds good to me - would you also recommend that for real mode 286? I would assume things there are pretty much identical. I've never used it for 286 code, but I assume it will be fine. Difference with 8086 isn't that big.

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Re: Hercules' 3D Prophet 4500 DirectX Version?

Posted on 2016-09-23, 09:46

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by Scali

in Windows

in Windows

But how's dithering helpful if the game uses 16-bit only resources? If they are 32-bit but the game sets the render output to 16-bit mode, isn't it better to just use some wrapper to force 32-bit output? 16-bit doesn't have enough precision for doing actual alphablending. Therefore 16-bit renderers …

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Re: I've an idea: Let's get some game development going

Posted on 2016-09-23, 08:04

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by Scali

in Milliways

in Milliways

From what I know, OpenWatcom is the way to go for protected mode. For pure real-mode, maybe a 'classic' borland compiler with performance-sensitive bits converted to assmebler as you go. During development of 8088 MPH I switched from Turbo C++ 3.1 to OpenWatcom 1.9, because I found it to be nicer …

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Re: Hercules' 3D Prophet 4500 DirectX Version?

Posted on 2016-09-22, 09:53

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by Scali

in Windows

in Windows

Note that the software T&L wasn't implemented until a 2003+ driver. It was popular to have 3danalyze running with some games to start with the card at all (like bf1942 / nolf2). Much of the T&L compromise was marketed with the then unique tiled rendering, hidden surface removal, overdraw mitigation …

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Re: Hercules' 3D Prophet 4500 DirectX Version?

Posted on 2016-09-22, 09:40

by

by Scali

in Windows

in Windows

From Wikipedia: "Basically it is a 'false DirectX 7' card that supports just DirectX 6 features." It has software implementation of T&L. I think that is somewhat of a misnomer. Hardware T&L is only one of the features introduced in DX7. The Kyro II supports various things only supported in DX7 (or …

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Re: IBM PC AT BIOS hangs on UniPCemu's 286 emulation?

Posted on 2016-09-22, 07:08

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by Scali

in PC Emulation

in PC Emulation

Because the IBM AT has a 8042 controller, which connects to a PS/2 Keyboard (and Mouse on the second port)? PS/2 keyboards and mice weren't even invented until years later. The AT is from 1984, PS/2 is from 1987. The AT didn't have a mouse port. Back then people still used serial mice, if they used …

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Re: IBM PC AT BIOS hangs on UniPCemu's 286 emulation?

Posted on 2016-09-21, 17:10

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by Scali

in PC Emulation

in PC Emulation

Why are we even talking about PS/2? An AT is a completely different machine, and predates the PS/2 by a number of years. You're trying to run an AT BIOS on a 286 emulator. PS/2 doesn't enter the equation.

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Re: IBM PC AT BIOS hangs on UniPCemu's 286 emulation?

Posted on 2016-09-21, 13:16

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by Scali

in PC Emulation

in PC Emulation

0xAA(The self test passed result) is in AL instead of BL? It should be in BL. As you can see, it calls KBD_RESET. This reads from the keyboard, and copies AL to BL before it returns. So the last byte read by KBD_RESET should be in BL at that point. That is of course assuming that CX was not zero …

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