Re: Creative Sound Blaster 2.0 jumps to self on boot(8088 accurate CPU emulation)?

Posted on 2016-08-18, 09:16

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by superfury

in PC Emulation

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After enabling a special log of invalid commands sent to the DSP I notice it receives two invalid commands: Commands 08h and 55h. Both don't exist, according to this list: http://the.earth.li/~tfm/oldpage/sb_dsp.html. Looking at the Dosbox source code, command 08h is SB16 ASP get version, but why …

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Re: Creative Sound Blaster 2.0 jumps to self on boot(8088 accurate CPU emulation)?

Posted on 2016-08-18, 08:09

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by superfury

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I've modified the Sound Blaster code a bit: The timeout for command 0xF2 'IRQ Request' for the Sound Blaster DSP was 20ns instead of 20us(after comparing code to Dosbox's blaster.cpp ( https://sourceforge.net/p/dosbox/code-0/HEAD/tree/dosbox/trunk/src/hardware/sblaster.cpp ) My latest Sound Blaster …

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Re: Creative Sound Blaster 2.0 jumps to self on boot(8088 accurate CPU emulation)?

Posted on 2016-08-18, 07:32

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by superfury

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Hmmm... maybe an interrupt vector is missing(the Sound Blaster IRQ5 handler) for some reason? It has something to do with timing it seems, as 3000 cycles doesn't give the bug, but 8088 speed(4.77MHz accurate timing w/ 8088 CPU clock cycles) gives the bug. Maybe the reset command (which uses 20us …

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Re: Sound Blaster 1.X/2.0 on-board speaker?

Posted on 2016-08-17, 14:52

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by superfury

in Milliways

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Whoops. I have mistaked the volume knob for a speaker, after looking at the images again:p Almost forgot those cards have one:p Do modern sound cards still have one? (Had mobo intergrated sound since, like 10+ years, which don't have one(never seen an onboard mobo volume knob) afaik)

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Sound Blaster 1.X/2.0 on-board speaker?

Posted on 2016-08-17, 13:56

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by superfury

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What was the on-board speaker on the Sound Blaster 1.X/2.0 used for? Could it only produce the test tone(2KHz sinus)? Was it enabled using the Speaker Enable/Disable DSP commands? Or is both the speaker and line out enabled/disabled using those commands? Or is the output switching between line out …

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Creative Sound Blaster 2.0 jumps to self on boot(8088 accurate CPU emulation)?

Posted on 2016-08-16, 15:47

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by superfury

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I get the following thing on the screen: Creative DOS Multimedia Architecture (v1.00) CTSOUND Physical-Level driver (v1.01) for Sound Blaster 2. Copyright (C) Creative Technology Ltd., 1993. All rights reserved. Driver Unit Number = 0 Base I/O Addx = 220 hex IRQ = 5 The program is executing a JMP to …

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Re: How 8088 corruption Sound blaster detection works?

Posted on 2016-08-15, 18:43

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by superfury

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i've made a little recording of: 1. The Sound Blaster playing 8088 corruption demo(until it crashes). 2. The Sound Blaster playing mike1984.tmv through 8088flex. 3. Playing m_8_22.wav, which fails. 4. Playing the doodle.cmf using Sound Blaster 2.0's play.exe(using Game Blaster emulation). The Game …

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Re: How 8088 corruption Sound blaster detection works?

Posted on 2016-08-15, 18:19

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by superfury

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A quick reinstallation of the Sound Blaster 2.0 disks seems to have fixed 8088flex. This is now running, although instead of proper sound I just hear ticks?

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Re: Properly emulating 80286+ multitasking protected mode with all exceptions etc.?

Posted on 2016-08-15, 17:56

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by superfury

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So it's actually fetching 64-bits at once from memory? Or does it only check the limit first(before fetching anything from the specified memory address), then starts retrieving data using byte/word/dword fetches? So it sees an offset of 0xFFFF, knows it's going to fetch 6 or 8 bytes from memory, …

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Re: Anything my unipcemu emulator still needs?

Posted on 2016-08-15, 17:01

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by superfury

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I've added mouse emulation to the finger OSK. Now mouse clicks and fingers will: - Press the emulated left mouse button when the left 1/3th of the screen is pressed(mouse)/tapped. - Press the emulated middle mouse button when the middle top 1/3th of the screen is pressed(mouse)/tapped. - Press the …

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Re: Anything my unipcemu emulator still needs?

Posted on 2016-08-15, 12:13

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by superfury

in PC Emulation

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I've added a simple full 104-key OSK to the emulator, which should work on Windows(which I'm testing on) as well as any touch-only device. Simply tap on the OSK status indicator (which now displays K(eyboard, previously not showing anything), M(ouse), G(aming) and the new O(SK) indicator, which …

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What is the value of a drained DRAM cell?

Posted on 2016-08-13, 18:10

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by superfury

in PC Emulation

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When the DRAM refresh is off or disabled for long enough a time, the DRAM cells in a IBM PC(/XT) are drained. What value do the cells return when this happens? Do they default to returning 1 or 0? So will the memory row that expires give 0xFF for all data or 0x00?

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How to add android support to existing SDL2 Windows project in Visual Studio?

Posted on 2016-08-13, 10:29

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by superfury

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I want to add Android/IOS support to my UniPCemu emulator, but the project is currently createn and configured for normal WIndows builds (just a normal WIndows native project). Is there an easy way to add the Android/IOS targets and support to the project without needing to create the solution etc. …

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Re: How 8088 corruption Sound blaster detection works?

Posted on 2016-08-12, 16:23

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by superfury

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I've worked on it a bit. Now the software, as well as 8088flex see my Sound Blaster 2.0 emulation(changing the DSP version from 2.01 to 2.00): https://bitbucket.org/superfury/unipcemu/src/1a066aa43d4d89f2646efe0052b75557e45313c3/hardware/soundblaster.c?at=master I see it initializing, then emitting …

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Re: Properly emulating 80286+ multitasking protected mode with all exceptions etc.?

Posted on 2016-08-12, 13:53

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by superfury

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This is what happens as far as I understand it now: 1. LIDT -1 => LIDT DS:[0xFFFF], since only 16-bit offsets exist in a 80286. 2. Then it starts to check the segment against it's limit(which cannot be higher than 0xFFFF), so it loads the first byte from memory offset DS:FFFF into a temporary/ …

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Re: Properly emulating 80286+ multitasking protected mode with all exceptions etc.?

Posted on 2016-08-12, 12:29

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by superfury

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So I was right in the LIDT loading data from 0xFFFFFF to 0xFFFFFF+6. But that wouldn't throw any exception, would it? It would simply wrap around to physical address 0x000000(24-bits address(lines)), resulting in byte 1-7 being read from memory locations 0x000000-0x00006 and actually loading that, …

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Re: Properly emulating 80286+ multitasking protected mode with all exceptions etc.?

Posted on 2016-08-12, 10:12

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by superfury

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You say it's because the segment limit is exceeded. But when -1 is loaded, the segment limit is effectively 0xFFFF? So address 0x000-0x800 fall within range, not triggering an exception? -1 is the pointer the idt base and limit are loaded from, not the base and limit itself and the read will be 5 …

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Re: Properly emulating 80286+ multitasking protected mode with all exceptions etc.?

Posted on 2016-08-12, 00:08

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by superfury

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Logically thinking, I see no reason why the 2nd byte and onwards should fail: the offset into the IDT(since it's a 32-bit CPU) can't wrap to 0(causing a fault because it exceeds 0xFFFF) with the interrupt vectors available(16-bits, meaning possible offsets 0-800h)? Or is this simply because, after …

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Re: Properly emulating 80286+ multitasking protected mode with all exceptions etc.?

Posted on 2016-08-11, 23:30

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by superfury

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You say it's because the segment limit is exceeded. But when -1 is loaded, the segment limit is effectively 0xFFFF? So address 0x000-0x800 fall within range, not triggering an exception?

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How 8088 corruption Sound blaster playback works?

Posted on 2016-08-11, 19:03

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by superfury

in PC Emulation

in PC Emulation

How does 8088 corruption detect the Sound Blaster? I've implemented basic Sound Blaster 1.0 commands atm, but it still isn't detecting it for some reason(Based on Dosbox code). The Sound Blaster 1.5 disks will crash when used with my 80(1)86/V20/V30 emulation. Anyone knows a good way to fix and test …

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