Rainbow 100 CP/M-86/80 BIOS Listings

This document contains the CP/M-86/80 BIOS (Basic Input/Output System) listings for the Digital Equipment Corporation (DEC) Rainbow 100 computer, first printed in March 1983. It serves as a technical reference, detailing the assembly code for the operating system's fundamental hardware interactions.

The document highlights several specific notes and known "differences" in the BIOS:

• A POP instruction is noted as missing in a section of code that is apparently never invoked.
• The PRMTVPVT code (Z80code.ASM) contains an incorrectly labeled argument in its multi-sector read routine (SECTN instead of SECNUM), though this typically does not cause problems as multi-sectored reads are not normally called by the BIOS.
• The diskette read/write code in Z80code.ASM has a timing "window" that can produce false "disk not ready" error messages.
• The SUBMIT command is identified as not working correctly when executed from a non-boot drive.
• The transient program area for a 64K Rainbow 100 computer is stated to be 47-1/2K bytes.

The majority of the document consists of detailed assembly code listings, including definitions for disk controller commands, system addresses for load and start, disk constants, PC-100 port addresses, and various subroutines for disk operations, error handling, memory management, interprocessor communication, and customized loader basic I/O system components.