Page:CTSS programmer's guide.djvu/9



Preface
This handbook is an attempt to document the techniques of using a current version (Model 13) of the compatible time-sharing-system (CTSS) which has been developed at the MIT Computation Center. It is primarily a manual of how to use the system, in contrast to many of the research memos, which have been more detailed in their documentation of the techniques of implementation. Because CTSS is basically a system which will allow an evolutionary development of time-sharing while continuing to allow more conventional background systems to operate, it is expected that the present manual will of necessity be revised many times before it reaches a final form. A good deal of the difficulty arises from, on the one hand, the rather drastic change in user operating techniques which time-sharing permits, and on the other hand the immense amount of programming required to fully implement the system.

The present work, although not highly polished, is being presented now to assist in this evolutionary process. It is expected to be a supplement to the Computation Center's Procedures Handbook which explains many of the general administrative details of the Center. Furthermore, a knowledge of programming is assumed of the reader. It has been our objective to present to an experienced programmer a reasonably complete manual which will allow him to use wisely the present version of the time-sharing system.

Because of the rapidity with which many of the features are being implemented, and the delays in distributing the inevitable revisions, some features are described here which are not yet accomplished. The reason for this is that it was felt to be important to indicate the intended scope and objectives of the system so that individual users could plan ahead in their applications. The features which are not implemented will be found listed in an appendix which will be revised periodically. In addition, each of the chapters can be expected to be periodically revised.

Since the present work is primarily a handbook, no attempt has been made to make any comparisons with the several other time-sharing