[NTLK] Newton MP2100 ROM Map

Matthias Melcher mm at matthiasm.com
Wed Aug 11 16:03:12 EDT 2010

Just for fun, this is a map of all the identified areas in the Newton ROM (well, those that I was able to clearly identify).

One pixel represents one word (four bytes), left to right, top to bottom. The colors are:
- black: the Unknown
- orange: the patch table
- red: ARM assembly code instructions (16000 function calls and close to one million instructions!)
- green: NewtonScript data (this includes images and sounds)
- yellow: all dictionaries
- blue: the ROM extension (Newton applications in ROM)

Shades of green denote the start of objects and refs. Black areas are mostly interleaved data that is used by the ARM CPU directly, or yet to be explored territory, or maybe even functions in the ROM that are never called.


Why is this useful?

Binary data in ROM can not be fully understood unless we know the use of all bytes. 

It's a bit like alphabet soup: the letters make no sense when the soup is stirred. But if the letters are in an order, like on a postcard, we can suddenly recognize words and numbers. We can immediately see which part is the message and which is the mailing address, the name, the street, the ZIP code. 

This map shows a Newton ROM postcard, only in the Newton ROM, we have eight million letters... .

 - Matthias

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