DOS 4.5 File and Volume Disk Management System

This publication describes the process and the products that Walland Philip Vrbancic, Jr., an Electrical Engineer, an Aerospace Senior Systems Engineer, and a Professional Programmer since 1983, created when he designed and programmed another enhanced Disk Operating System (DOS) for his Apple ][+ and for his Apple //e in order to manage Apple ][ Files and Volumes. Wherever he is able, Mr. Vrbancic has included source code samples, schematic diagrams, equations, figures, tables, and representative screen shots to help explain what he has created and the reasons why he did so. As in his previous Apple ][ DOS publications, this has been another incredible journey for him. With DOS 4.5 in particular, he has again re-imagined that time when he mostly lived, breathed, and worked on Apple ][ hardware and software development continuously for a good period of his life many, many years ago. The list of the incredible and powerful features that Mr. Vrbancic has engineered into his new DOS 4.5 File and Volume Disk Management System is staggering. DOS 4.5L boots directly into Main memory and sets HIMEM to 0x9600 whereas DOS 4.5H boots directly into Language Card memory and sets HIMEM to 0xBE00. Unlike the file buffers in DOS 4.5L, all five file buffers in DOS 4.5H are always available and they are fully contained in Language Card memory. Mr. Vrbancic has completed the full integration of the Lisa and the Big Mac assemblers into Auxiliary Memory and they both utilize DOS 4.5 File and Volume resources. Also, he has added additional logic to both assemblers so that they both now support the complete 65C02 instruction set. He has fully integrated both Sourceror and Big Mac and they both now support all SWEET16 opcodes. His newest C0:FF Apple //e ROM image is totally compatible with DOS 4.5 and this ROM image now fully supports the 65C02 processor, the SWEET16 metaprocessor, and his phenomenal GARBAGE routine which is based on Bongers' algorithm. His ROM image also includes a new HLIN routine which draws perfect HIRES line graphics for his celebrated ICON Maker tool that, when paired with his HIRES CHAR Editor and LENGTH tools, create stunning graphic presentations like those used in his Binary File Installation (BFI) software program. All the utilities, tools, schematics, Excel files, and Edraw files that Mr. Vrbancic utilized as his knowledge-base resources for the development of DOS 4.5 and for this publication can be requested through www.applecored.net.