Re: 8086 average clocks per instruction (when running normally)?

Posted on 2016-02-19, 22:38

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by superfury

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That .wav file would come in handy for comparing with the output of my emulator. It might be giving 'correct' output with 8088 MPH after all (Recording emulated output is also possible using it's sound menu option in the BIOS settings menu)? It's giving about correct results with the new Default …

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Re: How to make my sound renderer remove direct current for rendering audio?

Posted on 2016-02-19, 20:11

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by superfury

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I've changed the filters to use floating point all the way (except for samples to process from the emulated devices and output to SDL(which are signed 16-bit integer numbers)): OPTINLINE static float calcSoundHighpassFilter(float cutoff_freq, float samplerate, float currentsample, float …

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Re: How to make my sound renderer remove direct current for rendering audio?

Posted on 2016-02-19, 19:18

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by superfury

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Simply by ear it's generating a lot of noise, making the audio playing unhearable (like white noise sounding through the playing sound all the time, when there's sound being rendered(like a random signal generated using c/c++ and being sent to the speakers mixed together with the sound to play by …

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Re: x86EMU emulator releases

Posted on 2016-02-19, 19:03

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by superfury

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My latest build: x86EMU_20160219_1736.zip - Optimized rendering to work faster. - Optimized VGA rendering a bit. - Changed the 80(1)86/88 CPUs to use 8 cycles per instruction instead of the 4 cycles per instruction used on the other CPUs until actual cycle accuracy is implemented. - Decreased EMS …

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How to make my sound renderer remove direct current for rendering audio?

Posted on 2016-02-19, 16:32

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by superfury

in PC Emulation

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I want to prevent the emulator from sending direct current (of any voltage) to the output(SDL). If it does, it might be harmful to the speakers(DC kills the coil), depending on it's duration. Strangely enough, when I enable the high pass filter (frequency can be anything), it generates hard noise in …

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Re: 8086 average clocks per instruction (when running normally)?

Posted on 2016-02-19, 08:50

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by superfury

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One little question: if the carrier is at ~16.5kHz, won't the samples be distorted with high tones(above 16.5 / 2 = 8.25kHz frequencies in the song, when sampled at 16.5kHz?) Also, I'm still thinking on how to apply the different combinations of cycles in instructions universally to my instruction …

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Re: 8086 average clocks per instruction (when running normally)?

Posted on 2016-02-19, 01:31

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by superfury

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I don't have an XT(Nor do I think I'll ever have), so all I can rely on for now is the information I can find on the internet. I've just set it up to use 8 cycles/instruction on 80(1)86/88 CPUs and the old 4 cycles/instruction on 286+ CPUs. 8088 MPH worked somewhat(end credits music) with 4 cycles, …

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8086 average clocks per instruction (when running normally)?

Posted on 2016-02-18, 13:45

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by superfury

in PC Emulation

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When running average software or demos, what is the average amount of cycles spent per instruction on a 8086/8088 (e.g. Dosbox-style, but with actually ~4.77M cycles per second being counted and divided by this number is the exact instructions per second)?

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Re: x86EMU emulator releases

Posted on 2016-02-18, 08:35

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by superfury

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Actually it currently uses the PSP gamepad/PC joystick #0(when having at least as many buttons as the PSP has) for PSP-style input, keyboard on the PC for either PSP-style mapped input (during all non-Direct Input modes) and mouse/keyboard normal input during Direct Input mode. When no joystick is …

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Optimizing my VGA emulation to become fast?

Posted on 2016-02-17, 12:37

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by superfury

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As far as I can see, my accurate VGA emulation is currently the slowest part in my emulator (making the rest of the emulator slow too). Anyone knows how to make this faster? (It's already using some lookup tables for speeding it up) http://bitbucket.org/superfury/x86emu.git The VGA emulation modules …

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Re: x86EMU emulator releases

Posted on 2016-02-17, 11:44

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by superfury

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I don't know if this "libretro core" actually is a complete CPU core (my emulator already has one, which it uses for CPU emulation?) or simply an interface to use with emulators? Anyway, a little bugfix of BIOS settings file size and loading of Soundfonts (incorrect struct sizes due to packed bugs …

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Re: x86EMU emulator releases

Posted on 2016-02-17, 02:05

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by superfury

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My latest x86EMU build: x86EMU_20160217_0254.zip - Improved keyboard handling to properly support timed input in correct order(properly supporting special(ctrl/alt/shift) key combinations at the same moment of processing(like Gaming mode). - Converted keyboard to process input in linear time (first …

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Re: x86EMU emulator releases

Posted on 2016-02-15, 19:47

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by superfury

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My latest x86EMU build: x86EMU_20160215_2044.zip - Added drive-specific NDM bit to DMA checks. - Fixed Floppy IRQ lowering (shouldn't be done). - Disabled Floppy read write protected updating: This shouldn't be done (only on writes)? - Added Floppy abnormal termination to the log. - Added TC errors …

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MS-DOS 5.0 setup disk 1 hangs when starting setup?

Posted on 2016-02-14, 17:06

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by superfury

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When I try to start the setup procedure on MS-DOS 5.0 setup disk 1, I get the following log (when enabling the emulator debugger, which currently logs both instructions executed and floppy disk activity (except the actual data transfer itself, so only command, parameter, result phases and status …

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Re: x86EMU emulator releases

Posted on 2016-02-14, 16:34

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by superfury

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My latest x86EMU build: x86EMU_20160214_1720.zip - Implemented full FAT boot sector creation when creating floppy disk images. - Implemented Double Density and GAP length errors during floppy disk access (80286+ only, currently disabled with 80(1)86/88). - Fixed floppy creation boot sector bootstrap …

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Re: How does MS-DOS 5.0a format.com detect the correct floppy disk size to format?

Posted on 2016-02-14, 02:30

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by superfury

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I've found the bug preventing input during BIOS Menu's Direct Input mode and fixed it in the latest commit of x86EMU. This should make it easier to create the disk images.

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Re: How does MS-DOS 5.0a format.com detect the correct floppy disk size to format?

Posted on 2016-02-13, 23:53

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by superfury

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I just used the Dosbox build from Dosbox.com's link to Sourceforge. Maybe it's bugged? I see you've called it with -t floppy. I just called it using: imgmount a test.img Although, looking at some Dosbox fork (Dosbox-X?) tells me it will try to mount as hdd by default, which will fail? Can't it try …

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Re: How does MS-DOS 5.0a format.com detect the correct floppy disk size to format?

Posted on 2016-02-13, 23:24

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by superfury

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The code for generating is in the last commit to x86EMU. If you build it using the latest commit, just run it and in the bios settings menu, go to the disks menu, click/choose to create a floppy disk, choose the format(I'm testing using 1.44MB), type the name without .img and press enter to create( …

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Re: How does MS-DOS 5.0a format.com detect the correct floppy disk size to format?

Posted on 2016-02-13, 20:55

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by superfury

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It's a standard formatted as 80 cyclinders, 18 spt and 2 sides. It's also set in the boot sector correctly according to Winimage. The file size is also 1440KB (2x80x18x512 bytes), Why isn't it detecting it?

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Re: Is it legal to make my emulator create empty disk images with MS-DOS 5.0 boot loader code?

Posted on 2016-02-13, 20:45

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by superfury

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I've just tested it using PCE's xt-dos-plus and ibmpc machines. Both boot the floppy (when setting the image to boot to 0, no auto option?) in all their .bat configurations.

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