DOS 4.1 Disk Operating System Second Edition - Vrbancic, Walland

. .

Résumé :
DOS 4.1 is a newly imagined Disk Operating System for the Apple ][ computer, initially released in 2018. When the DOS 4.1 Manual was published, DOS 4.1 was not yet finished until Build 46 was completed in 2019. Designed and programmed by Walland Philip Vrbancic, Jr., a professional programmer and Electrical Engineer since 1983, DOS 4.1 contains the power and the flexibility he always thought DOS should have while remaining essentially compatible with DOS 3.3. DOS 4.1 Disk Operating System Second Edition describes all of the features that comprise DOS 4.1L and DOS 4.1H, including those features introduced by Build 46, using redesigned Tables, Figures, Schematic Diagrams, and example Assembly Language Routines. The following list are some of the features that have been engineered into the second edition of the DOS 4.1 Disk Operating System. DOS 4.1H boots directly into Language Card memory and sets HIMEM to 0xBE00. All five of its file buffers are fully contained in Language Card memory. DOS 4.1 supports the full 65C02 instruction set and it can now be used in both the Lisa and the Big Mac assemblers. Sourceror and Big Mac both support all SWEET16 opcodes. The ROM image described in this book supports the 65C02, SWEET16, and GARBAGE based on Bongers' algorithm. DOS 4.1 supports most Clock Cards which play an integral role in Volume and File timestamps. Volumes may be titled, numbered, and initialized to boot or to store files and data exclusively. Even track 0x00 is used to store files and data. Files are loaded into memory and saved using a page-accelerated algorithm. DOS 4.1 supports Applesoft CHAIN, File DIFF, File GREP, File LIST, File Undelete, Sector Display, Syntactical HELP (only in DOS 4.1H), and full lowercase command and argument input. DOS 4.1 has an expanded File Manager with additional Opcodes, and the Boot and Volume INIT functions utilize the same BOOTCFG Table. The Volume Catalog may use a minimum of a single sector and the CATALOG output may be terminated by pressing the ESC key at any time. DOS 4.1 uses the B keyword to implement the File Delete/File Save strategy for disk space conservation. DOS 4.1 can read DOS 3.3 Volumes, files, and data. DOS 4.1 can easily initialize Volumes with up to 48 tracks having either 16 or 32 sectors per track. All the source code and all the schematics can be requested through www.applecored.net....

Biographie:
All the source code and all the schematics can be requested through www.applecored.net.

Sommaire:
The utilities, tools, schematic diagrams, Excel files, and Edraw files that Mr. Vrbancic created and utilized for his knowledge-based resources in the development of DOS 4.5.06 and for this publication can all be obtained through www.applecored.net as TAR files. Walland Philip Vrbancic, Jr., received his BS degree in Zoology in 1970 from the University of California, Los Angeles. In 1973 he obtained a post-graduate degree as an Orthopedic Physician's Assistant from the University of Southern California Medical Center. While he worked as an OPA for over nine years, he studied Electrical Engineering at California State University in Long Beach. In 1980 he was graduated with a BS degree in Electrical Engineering from that University. He joined the Space Shuttle Simulation Laboratory at Rockwell International in Downey, California, in November, 1980, which was about five months prior to the launch of STS-1. It was at this time he became fascinated with the Apple ][ computer. While Mr. Vrbancic worked at Raytheon beginning in 1985, he began designing, developing, and programming very, very High Speed Data Transcription Engines and its Real Time software for tactical radar and sensor systems that were hosted on SGI high-end graphic computers. The most significant and celebrated software project that Mr. Vrbancic designed, developed, and programmed for Raytheon was a Digital Playback System. As Mr. Vrbancic observes I have always viewed software development as a set of very complex strategies that involve highly developed problem solving techniques. To develop such programming skills requires passion, perseverance, and practice. One cannot be expected to perform a Fiorillo Caprice overnight without expending a little passion, a little perseverance, and a little practice. Learning how to utilize and manage the memory of the Language Card partition in the Apple ][ computer is, in itself, very complicated, problematic, and certainly not intuitive. When that memory is managed correctly, the utilization of the Language Card partition provides great opportunities to expand one's programming skills. But those skills are still considerably simple compared to the skills that are required to utilize and manage Auxiliary memory. Only with passion, perseverance, and practice will the Apple ][ hardware reveal itself and yield its total computational power to that competent software and hardware engineer....