Debugger Images for Hammer and Newtsbug In this directory, you'll find debugger images for the two low-level debuggers of the Newton. Newtsbug needs a ROM image which is the AIF made out of the source of the ROM, with more or less symbols exported. Hammer needs the same image plus a high image which is the ROM Extension 0 of your Newton or very similar (type: rex0, creator: HMR6). Hammer will work with your Newton's REX0. Both images are included for 2.1 models and the MP120 US. You'll find only the AIF for the MP120 D and the MP130 US here. You can create the high image with Newtsbug. Please note that you should be familiar with Newtsbug to do that. Look for the last occurrence of RExBlock in the ROM (between 00000000 and 08000000). Newtsbug only allows you to search a long, so look for 52457842 ('RExB') and check by displaying the memory that it's followed by 6C6F636B ('lock'). Alternatively, you can dump the whole ROM (Save Memory from the File menu) and do all that on the Mac with an Hex editor. The fifth ULong after this signature is the length of the ROM Extension (> 840 KB on the MP2x00 US) (Cf OS600:ROMExtension.h). Just dump the whole extension (Save Memory from Newtsbug) and name the file with the same name as the ROM Image but replace 'image' by 'high'. Put it next to the AIF. You can set the creator and the type as noticed, but it's not required.