Introduction

Although the preceding sections have detailed some of what is to come, and how it will work, the introduction is still necessary. Broadly speaking there are four parts to this document including this introductory section. The bulk of this document will be taken up with parts on the areas of ROM hacking (graphics editing, text editing, multimedia editing and game logic) and a more free form part where the reader is shown some examples of hacks, methods and games in an attempt to convey some real world basis to a lot of the examples in the more general section that it would have been too unwieldy to keep in that part, too troublesome to categorise them or if they are otherwise little curiosities discovered over the years (it is these little curiosities that keep things interesting for many ROM hackers).

Traditionally in such guides something borderline philosophical or general tends to be said about now and there is little need to break from tradition right now. To this end concerning the qualities that make for a good ROM hacker they are arguably patience, or perhaps a deep down acceptance that every problem in computing can be solved, and near boundless curiosity. Great ROM hackers have come from all walks of life but most interestingly it seems traditional education, good experiences or bad within it, is not necessarily a great indicator of how well a person will take to ROM hacking.

The tools of the trade are many and varied but they can usually be broken down into five basics with only really the last being ROM hacking specific.

1. A hex editor. Unless quantum computing appears and takes over tomorrow all computers you will deal with boil down to binary (covered later but this is the 1 and 0 stuff) which is very simply abstracted to hexadecimal. It is usually ill advised to do anything more than viewing a format as a broad whole, looking in depth for a pattern or at small section, or making a simple change (be it a simple edit of a line, a find and replace, a basic operation or inserting something new) in a hex editor but those small changes can be the thing that makes a ROM hack work. 1a could be said to be a compression handling tool as compression is quite often standardised and often provides an immediate and, these days at least, simply worked around barrier to seeing a format as the program itself will see it.
2. A spreadsheet or some method of being able to manipulate/do repeated operations on a large list of numbers (in hexadecimal or otherwise). Computers are largely just tools for repeated manipulation of numbers, anything more usually coming at a steep cost in terms of resources required, so being able to manipulate large lists of numbers is useful.
3. A text editor. Related to the above two it is often beneficial to be able to manipulate sections of text and hexadecimal and perform extended searches upon them which is an arena text editors have long had serious abilities in.
4. A web browser. Although you will often be pulling things apart that have never been pulled apart before (and as high level programming languages become more viable for systems of the day that can be more true than ever) you will also be standing upon the shoulders of others all the time. To this end being able to see what others have done before you and research the underlying methods is very much necessary. As the doorway to the technical world these days is a web browser…
5. A tile editor. Used correctly a hex editor will allow you to see patterns in code and text but graphics are a huge part of nearly all games so being able to see graphics is immensely useful. See also the note on compression for hex editors as it can apply even more here (in a hex editor you can reasonably still follow what is going on but anybody that uses a tile editor for more than a few minutes will usually see how a mess of pixels can turn into a viewable image very quickly and be broken just as easily).

A familiarity with the basic usage of the command line (running something from one using some switches, the idea of piping and how to create a batch file at the level of just a series of commands) and the usage of a spreadsheet (what cells are, the fill command and how to enter basic functions) will be useful but any specifics or more complex concepts will be covered where appropriate.

Your computer to do all this does not necessarily have to be that powerful by the standards of any day, and especially in present times. Naturally there are techniques like some of the high end searching, some compression related activities and emulation of other consoles that push systems hard but a lot of damage can be done with considerably more modest systems. The added bonus of taking up ROM hacking compared with pulling apart real world devices (although such activities are also great fun) is that provided suitable backups are in place, and you really should get into the practice of making regular and preferably incremental backups of your work (some mention of methods by which you can do this is made in part 3), any damage can be undone by pressing undo or copying and pasting something else in, not to mention the further bonus of it allowing you to take many branching paths in an attempt to solve your problem. However many will suggest that if you can get a machine with at least two monitors of reasonably high resolution you will be doing well.

On jargon. Without going back to the philosophical pondering elsewhere in this part or contemplating some of the more extreme areas of physics there comes a point where describing something becomes needlessly long winded so it is abstracted to a term or series of terms at the cost of having someone somewhere (somewhen?) lack a frame of reference for it. Hopefully any technical terms encountered will be explained in the paragraph, have been explained before it or are not of immediate relevance to the matter at hand. Note that this definition differs slightly from The Jargon File’s definition.