1 :Bus Error
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.
2 :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.
3 :Illegal Instruction
If the computer tries to execute an instruction that isn't in its vocabulary, you see this error code. It's less likely than error 02, but still very common.
4 :Zero Divide Error
This error occurs if the CPU divides two numbers, and the divisor is zero.
5 :Range Check Error
An instruction is used to check if a number is within a certain range, if not, this error is displayed.
6 :Overflow Error
An overflow condition results if a generated number is too big for its allotted space.
7 :Privilege Violation
The 68000 runs in Supervisor or User mode. The Macintosh should always be in Supervisor mode as some instructions can only be used in this mode, but sometimes it is placed in User mode. This error results if an Supervisor instruction was run in User mode.
8 :Trace Mode Error
A programmer can use a runtime debugger while in Trace mode. This allows tracing through a program one instruction at a time. You see this error if a debugger isn't installed and the 68000 is accidentally placed in Trace mode.
9 & 10 :Line 1010 & 1111 Trap
There are many routines in the Macintosh ROM that can be called by placing instructions in a program that aren't in the 68000's vocabulary. When the CPU encounters such an instruction, it looks it up in the instruction table. If it finds that there's no entry for the instruction, you see one of these errors.
11 :Miscellaneous Hardware Exception Error
A Type 11 error is listed as a hardware exception error. However, Type 11 errors are more general in nature, and usually have nothing to do with hardware problems – it more likely a software instruction trying to do something that the hardware cannot do. You may see more Type 11 errors on a Power Macintosh computer because of problems with the software-based 68k emulation.
12 :Unimplemented Core Routine
A programmer might set break points in parts of a program to inspect for errors. If a debugger isn't installed when a break point occurs, you see this error code.
13 :Uninstalled Interrupt
The Macintosh uses an interrupt to identify when devices like keyboards and disk drives need service. Routines must be available in memory to tell the computer how to service the device. If those routines aren't available, you see this error.
15 :Segment Loader Error
The segment loader is responsible for loading a needed program allocated segment into RAM. If the segment loader can't do this, you'll see this error.
17-24 :Missing Packages 0-7
If you get these errors, you probably have a damaged System file. Error codes 15, 16, 26, 27, 30, and 31 also come up when the System file is damaged.
25 :Memory Full Error
You've run out of RAM!
26 :Bad Program Launch
The application could not be executed.
28 :Stack Ran into Heap
This is a memory related error, basically it was trying to use memory that is already in use.
27,30-31
See error codes 17-24 :Missing Packets.