Walland Vrbancic has just released his latest version of Apple II DOS, DOS 4.3 File Management System. DOS 4.3 is based on his earlier release of DOS 4.1H in 2019. DOS 4.3 boots directly into Language Card memory. It retains all of the enhancements found in DOS 4.1 with many more additional features.
Most notable are commands to directly modify disk sector data, update file time stamps at any time, control disk tracking to a single phase, configure eight areas of DOS that manage input/output data usage and display, and a new HELP command implementation.
Mr. Vrbancic also presents his porting of the Big Mac and Lisa assemblers to Auxiliary memory and their interfaces to DOS 4.3, all of which reside in their respective Language Card memory. He shows how to programmatically generate the Write Nibble table from the Read Nibble table code for the RWTS manager using only three additional 6502 instructions!
The manual for the DOS 4.3 File Management System may be purchased from the Lulu.com bookstore or from Amazon.
All of his DOS 4.3 source code for his tools and utilities, the Excel files, and the EDDX circuit schematics may be download from his website applecored.net.