Due to a restrained information politic of the manufacturer, there is not much known about the inside of the very successful Home Computer TI99/4A. This book therefore shall help the interested user to look into the secret of the operating system of the TI99/4A.

In individual chapters the commented listings of the ROM's and the 3 GROM's contained in the TI99/4A are explained i.e. the complete operating system including Basic. The contents of this book is completed by a listing of all commands, used in the Graphic Programing Language and by short explanations to the commented listings.