Re: Finding bugs in 8086-80386 emulation core?

Posted on 2017-07-25, 18:45

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by superfury

in PC Emulation

in PC Emulation

Having looked at osdev.org's FDC information, my Floppy Specify command(a.k.a. Fix drive data) was generating an IRQ, which it shouldn't(apparently). Fixing this, the Compaq Deskpro 386 BIOS boots without problems again.

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Re: CGA timings (again)

Posted on 2017-07-25, 09:43

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by superfury

in PC Emulation

in PC Emulation

Essentially the effect is the same as the VGA using pixel doubling in 640 pixel mode(UniPCemu translates all rendering timing on the CGA to VGA compatible values(not on the CRT raster itself). Only the raster timings, which drive the virtual CRT beam and display areas(active display, overscan, …

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Re: Finding bugs in 8086-80386 emulation core?

Posted on 2017-07-24, 22:20

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by superfury

in PC Emulation

in PC Emulation

I've just fixed a little bug in the FDC seek/recalibrate(Missing seek bit in MSR and IRQ) and Specify(Missing IRQ) commands. Now the Compaq Deskpro 386 BIOS hangs with POST Diagnostics code being A8? So problem detecting drive type? AT still fails the FDC after seeking? Edit: Looking at the executed …

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Adding El Torito support to the Compaq Deskpro 386 BIOS?

Posted on 2017-07-24, 14:12

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by superfury

in PC Emulation

in PC Emulation

Is it possible to add El Torito booting CD-ROM support to the Compaq Deskpro 386 using a seperate BIOS expansion ROM? I've noticed iPXE, but it doesn't seem to compile on MinGW32(MSYS2 installation): [BUILD] bin/process.o In file included from :0:0: core/process.c: In function 'process_add': core/ …

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x86 Modern BIOS low ROM mapping? e.g. SeaBIOS

Posted on 2017-07-24, 11:47

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by superfury

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What's the mapping of modern BIOS (flash) ROMs, like seaBIOS, in the UMA? I've currently mapped the ROM at both the end of 4GB(so reset vector at FFFFFFF0, the final byte of the ROM at FFFFFFFF) and high 1MB(the final byte being at FFFFF). In the case of SeaBIOS, the ROM is 256KB in size, so the ROM …

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Re: CGA timings (again)

Posted on 2017-07-24, 09:30

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by superfury

in PC Emulation

in PC Emulation

157.5MHz/11 is the 14MHz used by the PC? I've always thought it was simply 14.31818MHz(Used in current UniPCemu builds). I'll adjust the clock right away. Edit: Not needed, it seems: UniPCemu got 15.75/1.1, which is the same as 157.5/11.

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Re: UniPCemu emulator releases

Posted on 2017-07-22, 20:49

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by superfury

in Release Announcements

in Release Announcements

I've been working on the Android executable a bit, adding a few improvememts: https://www.dropbox.com/s/8gkxg08ko1imbpf/UniPCemu_20170722_2220.apk?dl=0 Changelog: - Improved handling of time-critical Android-specific events, now handling them in an seperate event handler(critical events only, like …

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UniPCemu ET3000/ET4000 15-bit and 16-bit high resolution (640x480 modes+) problems?

Posted on 2017-07-22, 17:43

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by superfury

in PC Emulation

in PC Emulation

When I try to emulate the ET3000/ET4000 15-bit and 16-bit color tests at 640x480 and higher resolutions with UniPCemu and the WHATVGA application, text printed in those modes end up with 'holes' in their output? Like someone is taking circular holes out of printed text(in graphics mode!)? Anyone …

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Re: CGA timings (again)

Posted on 2017-07-22, 17:37

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by superfury

in PC Emulation

in PC Emulation

Whoops. You're correct about them being minus one. Sometimes forget those, as I've long since implemented those in UniPCemu. The only parts I'm looking at nowadays are the character clocks themselves with the SVGA cards, as they're the only problems still left(like 8-bit and 15/16-bit color graphics …

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Re: CGA timings (again)

Posted on 2017-07-22, 16:37

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by superfury

in PC Emulation

in PC Emulation

As far as I know, it generates pixels just like a VGA, so using the base 14.31818MHz clock, 14318180 pixels clocks each second. That never changes. The only thing ever changing is the amount of clocks each scanline, which is always a multiple of 8 clocks plus horizontal adjust clocks. This is then …

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Re: UniPCemu emulator releases

Posted on 2017-07-20, 14:51

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by superfury

in Release Announcements

in Release Announcements

A new UniPCemu release: https://www.dropbox.com/s/ww29fcueq6y1ocq/UniPCemu_20170720_1551.zip?dl=0 Changelog: - 80386SX/DX is now emulated, on a Compaq Deskpro 386 with u13/u15 ROM support added. - CD-ROM emulation on 80386 is now working (tested with VIDE-CDD.SYS driver and MS-DOS 6.22 MSCDEX.EXE). …

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Re: Making UniPCemu faster on Android?

Posted on 2017-07-20, 00:28

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by superfury

in PC Emulation

in PC Emulation

So, when optimizing the view for fullscreen Android(by picking the most visually pleasing video settings with old-style NTSC CGA and enabling all sound hardware, setting the CPU for 8088@4.77MHz), it's now running at 8%. So, while there's still some optimizing and speed improvements left, it's …

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Re: Making UniPCemu faster on Android?

Posted on 2017-07-20, 00:00

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by superfury

in PC Emulation

in PC Emulation

Just found the cause of the odd Android(and probably PSP too, since they're both rendering the exact same way, although different screen resolutions are used) slowness bug: the renderer was constantly rendering 'dirty' frames. But the frames weren't dirty at all: the renderer keeps a flag when …

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Re: Making UniPCemu faster on Android?

Posted on 2017-07-19, 22:18

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by superfury

in PC Emulation

in PC Emulation

After messing about with the UniPCemu settings(on a Samsung Galaxy S7), I found out something: The extreme slowness happens only when setting the Direct Plot setting in the video menu to forced? Setting it to automatic or disabled makes it run at ~700K cycles/second emulating a 8088@4.77MHz(with 14. …

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Re: OAKCDROM.SYS rejecting UniPCemu's CD-ROM device after Inquiry?

Posted on 2017-07-19, 17:40

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by superfury

in PC Emulation

in PC Emulation

After extending the kept information to keep all information about the previous execution point, I've end up at 1934:0FAE. So that should be the cause of the invalid instruction, if not sooner. Edit: I cannot find anything other than that location. 1934 is the program executing, but the exact start …

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Re: OAKCDROM.SYS rejecting UniPCemu's CD-ROM device after Inquiry?

Posted on 2017-07-19, 17:24

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by superfury

in PC Emulation

in PC Emulation

The installer is working properly now, but cannot run because MS-DOS and the CD-ROM drivers(+HIMEM.SYS and mouse driver) take up too much Conventional memory. So I tried adding EMM386.EXE from MS-DOS 6.22 after HIMEM.SYS and loaded some other device drivers high. Now, after fixing the CPU to mask …

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Re: OAKCDROM.SYS rejecting UniPCemu's CD-ROM device after Inquiry?

Posted on 2017-07-19, 14:40

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by superfury

in PC Emulation

in PC Emulation

When looking at the disassembly of the VIDE-CDD.SYS/MSCDEX.EXE drivers, it looks like it's waiting a long time for the Drive Ready bit to lower? Edit: It seems to be waiting for the DSC bit to set? Edit: It was indeed expecting the ATAPI Seek command to set the DSC bit to identify it has seeked to …

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Re: OAKCDROM.SYS rejecting UniPCemu's CD-ROM device after Inquiry?

Posted on 2017-07-19, 13:52

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by superfury

in PC Emulation

in PC Emulation

Just tried executing the install.exe from the CD-ROM drive. It crashes and displays all kinds of garbage on the screen below the command prompt, together with a beep sound from the PC speaker. Edit: Found a little problem with detecting the disk size to be 4 times smaller than it's supposed to be( …

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Re: OAKCDROM.SYS rejecting UniPCemu's CD-ROM device after Inquiry?

Posted on 2017-07-19, 13:41

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by superfury

in PC Emulation

in PC Emulation

After modifying the drive access commands(stuff like reading TOC and CD-ROM data) to spin up the CD-ROM, it now proceeds to read the Primary Volume Descriptor off the CD-ROM! :D Something strange is happening as well: when a CD-ROM is already inserted when the drivers and MSCDEX are loaded, …

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Re: OAKCDROM.SYS rejecting UniPCemu's CD-ROM device after Inquiry?

Posted on 2017-07-19, 12:59

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by superfury

in PC Emulation

in PC Emulation

After having fixed that, it properly reads the TOC and tries to execute a read(10) command. This command simply aborts, because the drive isn't spinning?

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