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Action	Windows	Macintosh OS
Copy to Clipboard	Control + C	Command + C
Paste from Clipboard	Control + V	Command + V
Cut to Clipboard	Control + X	Command + X
Undo last command	Control + Z	Command + Z

TOPIC ———————————————————–

This article explains what some Macintosh system errors actually mean. You can use them to interpret what is happening when your Macintosh gives these errors.

DISCUSSION ——————————————————

Because the Macintosh is a complex operating system, the problems a user encounters can be equally complex.

These are example of some problems that may occur:

* A handle can be de-referenced.
*ÊA routine can get a NIL pointer.
*ÊThe stack can dip into the heap for just a few cycles and not be
caught by the stack sniffer.
* An application can forget to check an error code.

A Macintosh usually crashes with a system error code while running under System 6.0.x. System 7 changed the way errors are displayed Ð instead of displaying an error code, it translates the code to the appropriate words, like “Address Error”.

Finding out what’s wrong involves use of debugging tools, intricate knowledge of Macintosh memory structures, and familiarity with the application itself. Fixing it usually involves recompiling the source code. The table below explains some of the codes.

ID=01 Bus Error
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This means the computer tried to access memory that doesn’t exist. You can get this error on almost any Macintosh. If one of these computers tried to access one or more bytes beyond the total number of bytes in RAM, you see a bus error. You should never see this error on a Macintosh Plus or SE, because address references that are out of bounds “roll over”. This means if one of these computers tries to access one byte beyond the total bytes in RAM, it actually accesses the first byte in memory. If you see this error on a Macintosh Plus or SE, it’s reporting the wrong error or having hardware problems.

ID=02 Address Error
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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.

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