Cannot Map SheepShaver Data Area: No Error

About SheepShaver, a PPC Mac emulator for Windows, MacOS X, and Linux that can run System 7.5.3 to MacOS 9.0.4.

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thevisualboy37
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Posts: 9
Joined: Mon Jul 23, 2012 3:09 am

Cannot Map SheepShaver Data Area: No Error

Post by thevisualboy37 »

Hi all,

I know, there have been several posts about this, but my situation is different. Since probably 26 December 2020, every time I try to open SheepShaver, I get the dreaded "Cannot map SheepShaver data area: No error" error.

I am aware of why this is happening, but unfortunately... rebooting my host machine does not fix the problem. I also attempted to uninstall the one program I installed before I had this error, which runs in the background; no dice.

Host OS: Windows 10, build 1909
Host CPU: Intel Core i5-7600K (3.8 GHz, not overclocked)
Host RAM: 16 GB, 4.7 GB in use when attempting to run SheepShaver
SheepShaver build: 22 September 2020, 23 December 2020, 1 March 2015 (fallback; I tried using an older version, which had been working before also, in the vain hopes that it was an issue with GTK being included with the newer builds).
SheepShaver RAM: tried at 512 MB and lower, all the way down to 4 MB

I also tried doing a "reinstall", so to speak, of SheepShaver. Still no dice. My current prefs are shown below:

disk D:\SheepShaver\macos9.hfv // Drive letter is correct
extfs
screen win/800/600
windowmodes 3
screenmodes 63
seriala COM1
serialb COM2
rom D:\SheepShaver\Mac_OS_ROM
bootdrive 0
bootdriver 0
ramsize 536870912
frameskip 0
gfxaccel true
nocdrom false
nonet false
nosound false
nogui false
noclipconversion false
ignoresegv true
ignoreillegal false
jit true
jit68k false
keyboardtype 5
hardcursor false
hotkey 0
scale_nearest false
scale_integer false
cpuclock 0
yearofs 0
dayofs 0
mag_rate 0
swap_opt_cmd true
keycodes false
mousewheelmode 1
mousewheellines 3
idlewait true
keycodes false
mousewheelmode 1
mousewheellines 3
enableextfs true
debugextfs false
extdrives D
pollmedia true
etherpermanentaddress true
ethermulticastmode 0
routerenabled false
ftp_port_list 21
portfile0 C:\B2TEMP0.OUT
portfile1 C:\B2TEMP1.OUT

My alternative, currently, is to just use Qemu, but while I do love its improved accuracy compared to SS, I have several issues with it (this is not the place to detail my grievances, so I won't here). Is there any other solution that I'm missing?

-Johnny
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Cat_7
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Posts: 5242
Joined: Fri Feb 13, 2004 8:59 am
Location: Sittard, The Netherlands

Re: Cannot Map SheepShaver Data Area: No Error

Post by Cat_7 »

Hi,

Yes, that is a nasty error for which we do not have a clear solution.
There is no guarantee, but you might want to try setting:

ignoreillegal true
jit false

Disabling the jit will make things go slower, but it might solve your issue.

Best,
Cat_7
thevisualboy37
Space Cadet
Posts: 9
Joined: Mon Jul 23, 2012 3:09 am

Re: Cannot Map SheepShaver Data Area: No Error

Post by thevisualboy37 »

Thank you for the suggestion. Unfortunately, I'm still getting the same error.

EDIT: This may or may not be helpful, but I also downloaded the 23 December 2020 build of BasiliskII (which I think is based on the same or similar code?), and it doesn't give me that error.
thevisualboy37
Space Cadet
Posts: 9
Joined: Mon Jul 23, 2012 3:09 am

Re: Cannot Map SheepShaver Data Area: No Error

Post by thevisualboy37 »

Well, I believe I finally figured it out... I think it was my webcam! I was on the right track with trying to uninstall its software (which always ran in the background and wouldn't let me close it), but as soon as I unplugged it and rebooted my computer, it now works perfectly!
thevisualboy37
Space Cadet
Posts: 9
Joined: Mon Jul 23, 2012 3:09 am

Re: Cannot Map SheepShaver Data Area: No Error

Post by thevisualboy37 »

...And never mind, it was just a fluke.
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adespoton
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Re: Cannot Map SheepShaver Data Area: No Error

Post by adespoton »

thevisualboy37 wrote: Mon Jan 11, 2021 3:24 pm ...And never mind, it was just a fluke.
It wasn't your webcam that was the issue, it was the memory mapping on your host OS. Rebooting cleared memory, which let SheepShaver allocate memory at the fixed address it likes to use.

Since then, something else has allocated that memory, so your error is back. Dynamic memory addressing plus ASLR in Windows can make this a pain to debug.
thevisualboy37
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Posts: 9
Joined: Mon Jul 23, 2012 3:09 am

Re: Cannot Map SheepShaver Data Area: No Error

Post by thevisualboy37 »

adespoton wrote: Mon Jan 11, 2021 4:19 pm Rebooting cleared memory, which let SheepShaver allocate memory at the fixed address it likes to use.
Rebooting doesn't always fix it, for some strange reason.
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adespoton
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Re: Cannot Map SheepShaver Data Area: No Error

Post by adespoton »

thevisualboy37 wrote: Mon Jan 11, 2021 5:32 pm
adespoton wrote: Mon Jan 11, 2021 4:19 pm Rebooting cleared memory, which let SheepShaver allocate memory at the fixed address it likes to use.
Rebooting doesn't always fix it, for some strange reason.
That's because sometimes something else loads at memory address 0 after boot. It's Russian Roulette every time.
thevisualboy37
Space Cadet
Posts: 9
Joined: Mon Jul 23, 2012 3:09 am

Re: Cannot Map SheepShaver Data Area: No Error

Post by thevisualboy37 »

Well, it seems as though a recent Windows update broke "Fast Startup". I've now had that disabled for about a week, and so far I have had no more errors with SheepShaver. This can't be a coincidence; the problems first started happening after the update. Prior to that, I never encountered this error even once.
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