Documentation for PSXSDK.
Format is Ascii doc.
PSXSDK itself can be found here: http://code.google.com/p/psxsdk/
If you want to compile psxsdk.adoc in some user-friendly format, you need such programs:
asciidoc - converter from adoc to html source-highlight - for highlighting pieces of C source code in result document (optional)
To convert document into html just run make(if you are under Linux or *BSD).