Rainbow 100 CP/M-86/80 Software Design and

This document serves as a design and maintenance manual for the CP/M-86/80 operating system on the Digital Equipment Corporation Rainbow 100 computer, an enhanced version of CP/M-86 V1.1. Its primary focus is detailing how the operating system facilitates the execution of programs (transients) on both the Z80 and 8088 processors.

Key aspects covered include:

• System Organization: Describes memory configurations for 8088 and Z80 transients, emphasizing dynamic reconfiguration to maximize the Transient Program Area (TPA) for the active processor.
• Cross-CPU Communication: Explains the intricate message packet and interrupt-driven communication protocols between the 8088 and Z80, including how they swap master/slave roles.
• Operating System Components: Provides in-depth descriptions of patches made to the Command Console Processor (CCP) and Basic Disk Operating System (BDOS) within CPM.SYS to support Z80 transients. It also details the structure and functions of the BIOS, covering initialization, character I/O routines (logical, physical, hardware drivers, I/O redirection), interrupt handlers, disk I/O routines (blocking/deblocking, error handling), and utility subroutines.
• Interface Layer and Primitive Routines: These modules are crucial for managing cross-CPU communication and providing low-level services like disk I/O and data movement within Z80 memory.
• Pseudo BDOS/BIOS: Outlines how Z80 transients request services from the 8088 via pseudo routines that manage parameters and interrupt the other CPU.
• System Disk Generation: Provides comprehensive instructions, including required tools and source files, for preparing and placing system files (e.g., BOOT100.SYS, CPM.SYS, Z80CCP.SYS) and utility files on system and data tracks.
• Specific Modifications: Mentions modifications to system utilities like SUBMIT.CMD for user-selected boot drive control.

Overall, the manual provides technical insights into the dual-processor architecture, inter-processor communication mechanisms, and the internal workings necessary for the development and maintenance of software on the Rainbow 100's CP/M-86/80 environment.