The format of chapter heads may be controlled by the command
\mychapter{<head1>}{<head2>}
Here <head1> is the chapter heading to use when the chapter is
numbered and <head2> is the heading to use with the
\chapter* command. The text of the \chapter command is
referenced in <head1> and <head2> by writing #1.
For example, the default chapter head is defined by\mychapter{\LARGE \sc \thechapter. #1}{\LARGE \sc #1}
Chapters always begin on a new page. The style parameter
\chaptopsep is the amount of blank space placed at the top of
the page before the chapter head, and \chapaftersep is
the amount of blank space placed between the chapter head and
the text. They are initially .5in. They may be changed
by the \setlength command.
The default head does not have the word ``Chapter'' preceding the chapter number, which is fine with me, but may not please you. To get back something approximating the original LATEX heads try
\mychapter{\huge \bf \chapapp\ \thechapter\\[20pt]\Huge\bf #1}
{\Huge \bf #1}
The command \chapapp is ordinarily defined to be
``Chapter'' but the LATEX command \appendix changes it
to ``Appendix''. If you want more flexibility in your appendix
heads, use \mychapter to define them anew.