Re: Incorrect\hanging notes on Roland module. Defective? Fixable?

Posted on 2016-10-06, 18:34

by

by Jepael

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Just wanted to ask the question from my previous post again. Can CPU speed issues effect one external MIDI module without effecting another? I always assumed that CPU speed problems related to MIDI were created by the MPU401 interface (in this case an MM401), which would cause the issues to be …

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

Posted on 2016-10-05, 21:15

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by Jepael

in Milliways

in Milliways

So perhaps the timer rate should be much higher to alleviate that. Wolf3D uses 700Hz OPL IMF music (286 required), Monkey Island 473 Hz for OPL MIDI music (8088 playable). To be honest, I have no idea why they'd choose such high update rates. Sounds like whoever designed that was on crack :) IMF …

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

Posted on 2016-10-05, 19:21

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by Jepael

in Milliways

in Milliways

Yes it's slow, but not that slow. The amount of dummy reads depends on the speed of the machine of course, there is no need to do 35 dummy reads on a 4.77 MHz 8088. Pretty sure it's not. That is, port reads are more or less 'constant time'. That's why they can be used for delay, even on fast …

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

Posted on 2016-10-05, 15:32

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by Jepael

in Milliways

in Milliways

I had no idea. That's kind of obnoxious for a delay. I wonder if one might be able to stagger some of those commands (especially for simultaneous notes and program changes) to reduce the impact that programming the OPL2 has on timing. Or maybe interleave writing registers with some other …

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

Posted on 2016-10-05, 15:23

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by Jepael

in Milliways

in Milliways

And sure, there's GUS mod players for 286. But GUS is really 386/486 era thing anyway. Even with SB 1.x, the DAC could be better used for 8-bit PCM sound effects instead of using CPU horsepower for mixing even four channel music into 8-bit PCM. Sadly it's not quite 'free' on a low-end system. The …

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Re: Is it SAFE to plug a surge protector strip into a UPS

Posted on 2016-10-05, 14:19

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by Jepael

in Milliways

in Milliways

To me it sounds like they suggest using strips without any surge protection or filtering just in case, because usually one cannot tell if the strip has pure surge protection or maybe other filtering as well. If the power strip only has pure overvoltage surge protection (TVS, MOV, GDT), I think it …

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Re: Dune "HERAD" Ad Lib Music Hacking

Posted on 2016-10-04, 18:25

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by Jepael

in DOS

in DOS

I wanted to ask, will this reverse engineering project lead to a possible loader for AdPlug? I'd like to beable to listen to the Dune files endlessly. That's what I'm hoping for! I don't know how to program so right now, we're relying on others to come up with code for a loader for AdPlug or even a …

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Re: GeForce FX and scalling low resolutions

Posted on 2016-10-03, 19:34

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by Jepael

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I don't expect the display to support them, I just would like to know, is there any way to force the GeForce FX to doublescan the resolutions for the digital output. The VGA resolutions are already double-scanned on both DVI and VGA interfaces. My point was, even if the DVI output works just …

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Re: UniPCemu hard disk detected properly on XT-IDE XT, but not on XT-IDE AT?

Posted on 2016-10-03, 19:03

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by Jepael

in PC Emulation

in PC Emulation

It's both in 8-bit mode. Anyone can see why it won't detect the hard disks on AT, but it detects it on the XT(same settings used on both architectures): https://bitbucket.org/superfury/unipcemu/src/53b8f532523978157ca1e2de9c25b5ae7cbe4e08/UniPCemu/hardware/ide.c?at=master On the XT version it sends …

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

Posted on 2016-10-02, 14:32

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by Jepael

in Milliways

in Milliways

Ah, so it seems! That might explain a few things :) I've actually never had any EGA hardware.. But isn't that the limitation of the IBM 5154 monitor hardware to be backwards compatible with CGA signals (15kHz=RGBI, 22kHz=RrGgBb)? And so it is not a limitation of EGA card hardware itself, but because …

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

Posted on 2016-10-02, 10:08

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by Jepael

in Milliways

in Milliways

But even using 320x200 at 16 colors, VGA does let you customize the palette, while EGA doesn't. Yes, I know. I've played Duke Nukem II , as you can see from my avatar and username. That game, along with The Blues Brothers and Prehistorik , was memorable for using EGA video mode 0x0D with a custom …

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

Posted on 2016-09-30, 21:29

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by Jepael

in Milliways

in Milliways

That really depends on what you are trying to achieve. I have absolutely no idea how to write low level code (sound / video / input) for protected mode, so I would just stick to real mode (if I was to make my own DOS game). This applies to me also, I know real mode stuff pretty well and never done …

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

Posted on 2016-09-30, 20:38

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by Jepael

in PC Emulation

in PC Emulation

So what is the error code? Any logs on 8042 port accesses, read/write to 60h and 64h?

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

Posted on 2016-09-28, 20:09

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by Jepael

in PC Emulation

in PC Emulation

superfury wrote: Anyone can tell me why the BIOS errors out with a 403 keyboard error? The keyboard response timings are currently adjusted to 5ms after the command is received? Error 304 instead of 403? Command E0 response bit 0 must be low.

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

Posted on 2016-09-27, 19:44

by

by Jepael

in Milliways

in Milliways

I have a suggestion regarding level map format and editor. What if we pick a suitable format that already exists and has an editor? Camoto is a tool by Malvineous and could be made to support our custom format if we wanted to. Can also work with tilesets and adlib music. Also supports group/archive …

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Re: Turbo Pascal delay bug and the PC timer

Posted on 2016-09-26, 20:52

by

by Jepael

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I'm not sure if I have understood things correctly. If I want to get the mode for counter 0 and I have set the bits for the read back command, this just seems to return some random value when then reading from 40h. Own example code: function readpitmode:Word; assembler; asm mov al, 11000010b out …

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Re: Fixing a Acumos AVGA2

Posted on 2016-09-26, 17:36

by

by Jepael

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

If you are connecting it to VGA port of modern TFT monitor, please make sure (read the manual) that it supports 70Hz formats, because many modern TFTs don't.

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Re: After improving UniPCemu's UART it's Serial mouse it doesn't get detected anymore?

Posted on 2016-09-25, 11:18

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by Jepael

in PC Emulation

in PC Emulation

superfury wrote: What happens to partially sent packets when RTS becomes 0? Are they discarded(chip powers off)? It's the same as unplugging the mouse. The mouse chip loses power or goes into reset.

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Re: Turbo Pascal delay bug and the PC timer

Posted on 2016-09-25, 10:18

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by Jepael

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

For example http://wiki.osdev.org/Programmable_Interval_Timer or 8254 datasheet. This is normal. When in square wave mode (3), the timer counts only with even numbers, but it counts one period twice, to get square wave out. It counts once for high period and once for low period, so to the software …

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Re: After improving UniPCemu's UART it's Serial mouse it doesn't get detected anymore?

Posted on 2016-09-24, 23:31

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by Jepael

in PC Emulation

in PC Emulation

I think mice are different. You need to just cope with that or see how MS driver detects MS mouse or 3-button driver detects 3-button mice so you can emulate a specific mouse if you like. For what I can tell about my experience, which I recall was not manufactured by MS, the RTS is either power or …

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