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Important: This document is part of the Legacy section of the ADC Reference Library. This information should not be used for new development.
Current information on this Reference Library topic can be found here:
The Memory Manager will trigger an "ID=33" system error when, during some operation which
scans the objects in the heap, it sees that its running count of free bytes (
If you get this error, use a debugger (like Macsbug or TMON) when you attempt to reproduce the error, to check the consistency of the heap up to the point where the error occurs. You may need to do this repeatedly until you isolate the operation that is corrupting the heap.
Note that although the heap may become corrupted during a system call, this doesn't mean you've found a bug in the ROM; your code could be passing incorrect or invalid parameters to this or a previous system call, or could have corrupted a data structure used by a system call. More debugging is usually in order in this case; tools like Discipline (included in TMON; also available from users' groups and electronic services) can help detect invalid parameters in system calls. Also, there is a Macsbug command, AH, that can check the consistency of the heap on every system call. See the documentation that came with your debugger to see what special features it offers.
A note about "SysErr.a"
Technical Support is often asked for an up-to-date list of error codes. In general, this is provided in
"SysErr.a", the file of error numbers shipped with the most current version of MPW. Admittedly, the
documentation value of "SysErr.a" is sometimes low (as in the case of
The Memory Manager