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Multiple Mac CM games simultaneously?


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I guess OS 9.x doesn't have very good multi-threading to be able to handle two copies of CM being open simultaneously (multi-threading being one of the major improvments with the advent of OS X). I'm not absolutely sure about that being the reason for the errors you're seeing, but a Type 2 error is a fairly basic memory error. Other issues may be in what manner CM is programmed to utilize resources or certain programming API limitations, etc.

At what point do you get this error; right after opening up the second CM game or once you've reached a certain point within the game ?

[ December 18, 2003, 03:19 PM: Message edited by: Schrullenhaft ]

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Thanks for your reply Schrullenhaft.

"right after opening up the second CM game"

Just tested it to be sure. The Type 2-error message occurs immediately after launching the 2nd CM game after the 1st CM is running. Does not matter if it is CMBB or CMAK running.

I did my search to try and understand if there was anything that I could change to handle two copies of CM being open simultaneously. The explanation I found for the Type 2-error message was this:

ID=02 Address Error

The Motorola 68000 microprocessor can access memory in increments of one byte (8 bits), one word (16 bits), or one long word (32 bits). The microprocessor can access a byte of information at an odd or even memory address. But it must access a word or long word at an even memory address. So, when the microprocessor attempts to read or write a word or long word at an odd address, you see this error. Since that's a 50/50 proposition when running random code, this one shows up quite often.

Does this mean CM for Mac OS 9.x is a one game open only proposition?

Not complaining. Just looking for a little more user convenience. Being able to handle two copies of CM gmaes being open simultaneously is a good thing.

Thanks,

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Originally posted by Dawg Bonz:

The Motorola 68000 microprocessor...

...hasn't been used in a Mac for 8-9 years I think. That was pre-Power PC.

At a rough guess (because I'm not even approximately a Mac guru), both games are trying to grab the same memory and are colliding in the process, which is what causes them to crash. The cure for it would not be multi-threading (would it?) but protected memory, which is another feature of OS X. Unless protected memory is an integral part of multi-threading? (I told you I was no Mac Guru.)

Michael

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Thanks Michael.

Your explanation sounds reasonable to me. I know I have enough memory to run both games. I am just searching for better understanding about why two-CM games running in OS 9.1 won’t work when it looks like it should. More user convenience to have two games open. Sounds like the new CM game(s) in OSX should have no problem running simultaneously.

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It looks like OS 9.x doesn't have protected memory. I assumed it had such a feature since it could multi-task several applications and such a feature has been common to other OSes for years. I mistook the 'memory partitions' OS 9.x offered for each program (the reserving or assigning of memory to each program) as a form of protected memory. Apparently there are few, if any, safeguards to the application's access to this memory. Thus other applications could overwrite memory 'reserved' by other applications by just writing to it at will (without the OS stepping in to interfere with such a process).

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Thank you both, Schrullenhaft & Michael for your explanations

Good to know it is exclusively the ‘mature’ OS disability not untutored operator error type 2-3-4 etc. I can live with only one-CM theatre of operation operating on the machine. Hope the new OS X will be simultaneous CM game "protected memory" friendly.

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