Re: PCEm. Another PC emulator.

Posted on 2019-05-19, 17:00

by

by SarahWalker

in PC Emulation

in PC Emulation

V15 is now available. Changes since V14 : New machines added - Zenith Data SupersPort, Bull Micral 45, Tulip AT Compact, Amstrad PPC512/640, Packard Bell PB410A, ASUS P/I-P55TVP4, ASUS P/I-P55T2P4, Epox P55-VA, FIC VA-503+ New graphics cards added - Image Manager 1024, Sigma Designs Color 400, …

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Re: Adding CR4 bit 3 support only to 80386/80486 CPU emulation?

Posted on 2019-02-13, 19:36

by

by SarahWalker

in PC Emulation

in PC Emulation

Fair enough. Though the magic word there is 'embedded' - you wouldn't have seen those 486s in a regular desktop PC.

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Re: Adding CR4 bit 3 support only to 80386/80486 CPU emulation?

Posted on 2019-02-12, 20:21

by

by SarahWalker

in PC Emulation

in PC Emulation

Could someone have theoretically made a 486 with PSE? Yes. Did anyone actually make a 486 with PSE? No. Ergo, if you are trying to emulate a 486 then you shouldn't emulate PSE. Because such a chip does not exist.

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Re: Adding CR4 bit 3 support only to 80386/80486 CPU emulation?

Posted on 2019-02-12, 18:29

by

by SarahWalker

in PC Emulation

in PC Emulation

Define 'valid behaviour'. If you add those features then you aren't emulating 386 and 486 CPUs anymore.

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Re: Drive sound simulation in computer emulators

Posted on 2018-10-11, 18:55

by

by SarahWalker

in PC Emulation

in PC Emulation

SainT (Atari ST) simulates floppy sound - it's the first one I was aware of, and influenced me to add support in B-em.

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Re: DOS Lemmings with Digital Sound Effects?

Posted on 2018-09-05, 16:43

by

by SarahWalker

in Milliways

in Milliways

And yeah, I'm hoping someone has either the Sound Blaster Pro (1.0?) or 16/CD bundled version (or to find them myself) - if neither of those have digital sound, well, I'm stumped! Don't know if it's helpful, but I have the version bundled with the SB Pro v2.0 and it's the same as the retail version …

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Re: PCEm. Another PC emulator.

Posted on 2018-04-21, 09:04

by

by SarahWalker

in PC Emulation

in PC Emulation

DOS/V worked the last time I checked, so you should be able to run that version.

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Re: PCEm. Another PC emulator.

Posted on 2018-04-20, 13:24

by

by SarahWalker

in PC Emulation

in PC Emulation

PCem v14 is now available. Changes from v13.1 : New machines added - Compaq Portable Plus, Compaq Portable II, Elonex PC-425X, IBM PS/2 Model 70 (types 3 & 4), Intel Advanced/ZP, NCR PC4i, Packard Bell Legend 300SX, Packard Bell PB520R, Packard Bell PB570, Thomson TO16 PC, Toshiba T1000, Toshiba …

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Re: PCEm. Another PC emulator.

Posted on 2018-04-06, 18:44

by

by SarahWalker

in PC Emulation

in PC Emulation

Sorry - I manually approve new user registrations due to the number of spammers that try to register, and I must have missed yours. I couldn't find any sign of a 'vvbee' user - did you try under a different name?

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Re: PCEm. Another PC emulator.

Posted on 2018-04-05, 16:09

by

by SarahWalker

in PC Emulation

in PC Emulation

You are aware that there is a PCem forum, right? You might get more responses to your questions there than by extending this comically long thread.

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Re: motherboard has issues with sound-cards / Socket 3 confusion

Posted on 2018-03-23, 19:30

by

by SarahWalker

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

It could be that the faster CPUs are using a write back cache, and the board isn't configured properly for this. The manual I found had a bunch of CPU type jumpers in addition to the bus speed jumpers - are these all set correctly? What CPUs are you actually using with this board?

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Re: PCI vs ISA devices?

Posted on 2018-02-21, 17:36

by

by SarahWalker

in PC Emulation

in PC Emulation

Are ISA devices reported on the PCI bus(cf8-cff port range)? No. Or are they normally probed by e.g. Windows 95 and up? Yes - this is what the hardware detection phase during setup is doing. ISA has no universal mechanism for detecting cards - you have to probe manually for each device you want to …

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Re: PCem - possible to run in 320x200, and/or above 60hz refresh?

Posted on 2018-02-04, 17:10

by

by SarahWalker

in PC Emulation

in PC Emulation

PCem will scale the emulated display to whatever resolution/refresh rate your desktop is running at - it makes no attempt to change either.

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Re: PCEm. Another PC emulator.

Posted on 2018-02-02, 19:59

by

by SarahWalker

in PC Emulation

in PC Emulation

There might be optimisations there. But since PCem has the dynamic recompiler these days, why bother?

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Re: PCEm. Another PC emulator.

Posted on 2018-02-01, 18:08

by

by SarahWalker

in PC Emulation

in PC Emulation

I provided the benchmark results justifying those changes here : http://pcem-emulator.co.uk/phpBB3/viewtopic.php?f=4&t=877.

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Re: Unaligned memory access and bus width

Posted on 2018-01-24, 17:37

by

by SarahWalker

in PC Emulation

in PC Emulation

386 0W/S access = 2 cycles. As far as I've ever been able to tell, the 386 bus is just a wider version of the 286 bus. The 486 can drop down to 1 cycle but only as part of a 4-word burst when performing a cache fill.

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Re: Effect on POP (E)SP on the stack pointer?

Posted on 2018-01-24, 17:32

by

by SarahWalker

in PC Emulation

in PC Emulation

superfury wrote: Address size override has no effect on that? SP/ESP is determined by SS descriptor size(big bit) only? Correct. SP/ESP is indeed entirely determined by SS, and prefixes have no effect.

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Re: Effect on POP (E)SP on the stack pointer?

Posted on 2018-01-23, 21:30

by

by SarahWalker

in PC Emulation

in PC Emulation

No, because you've written to [SP] rather than [ESP]. So you've corrupted [0xFFFC] and the POP will then read whatever was at [0xFFFFFFFC]. If your code was : Copy code to clipboard 1 MOV ESP,FFFFFFFC 2 MOV [ESP],FFFC 3 POP SP then ESP will indeed be 0x0000fffc.

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Re: Effect on POP (E)SP on the stack pointer?

Posted on 2018-01-23, 17:55

by

by SarahWalker

in PC Emulation

in PC Emulation

On POP, the increment happens before (E)SP is assigned. So if 0x(ffff)fffc is what's on the stack, (E)SP will be 0x(ffff)fffc. You're using PUSH SP though, which adds complications. On 8088/8086 the value of SP that's written will be after it's decremented, so 0xfffa will end up on the stack and …

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Re: PCEm. Another PC emulator.

Posted on 2017-12-17, 09:18

by

by SarahWalker

in PC Emulation

in PC Emulation

PCem v13.1 is now available. This is a quick bugfix release, with the following changes from v13 : Minor recompiler tweak, fixed slowdown in some situations (mainly seen on Windows 9x just after booting) Fixed issues with PCJr/Tandy sound on some Sierra games Fixed plasma display on Toshiba 3100e …

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