Chapter 5: Disassembly of C000 and F000The original text of this book had a listing packed in 4 columns per page. This reduced the amount of paper used, and therefore the cost of the book. In electronic form, such measures are not required. So instead, this version of the book contains links to disassembly listings that were made and commented around 1985. These contain exactly the same information with same Acorn syntax (# for hex, @ for immediate), but in a less-cramped one-column per page layout and with comments. In addition, there are disassemblies that were not in the original book. It is hoped the reader will forgive this straying from historical authenticity in return for the improvements.
Note that the comments in these files were not made by the authors of this book, so conflicts and error may exist. Slightly different versions of the Atom ROMs may also exist. If you wish to recreate or modify
the firmware with a cross assembler, you will need source code in
a suitable format. Keith Howell has created source files that
assemble to the original binary code by using the assembler
section (ca65) of the CC65 C compiler for the 6502. This also
comes with a disassembler (da65) that produces source files
suitable for ca65. Visit: There is no commented disassembly of E000 - the DOS ROM. You can disassemble it with da65 yourself if required. The 8271 FDC chip it controlled has been obsolete and hard to find for many years, so not really worth disassembling unless you are trying to create a substitute DOS ROM. E.g. one that uses a memory card instead.
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