MS™-DOS Operating System, Version 2.11

This document describes the MS™-DOS Operating System, Version 2.11, an updated release that builds upon Version 2.05. Key new features include support for "The International Call System," which provides country-specific information like currency symbols and date/time formats, and the "Mini Exchange," a microprocessor-controlled switch allowing a Rainbow 100 computer to share up to eight devices (personal computers, printers, or modems) within a 60-meter radius.

The operating system offers fundamental capabilities for program execution, storage, and editing, and includes the SETPORT utility for configuring serial port and DIGITAL serial printer parameters (supporting devices like LA50, LA100-PC, and LQP02 printers). Core components like IO.SYS (Basic I/O system), MSDOS.SYS (Operating System Resource Manager), and COMMAND.COM (Command Interpreter) are outlined, along with a suite of utilities such as DEBUG.COM for testing, FORMAT.COM for diskette and Winchester disk formatting, MASM.EXE (Macro Assembler), LINK.EXE for linking object files, PRINT.COM for background printing, RECOVER.COM for bad sector recovery, and SORT.EXE for data sorting.

DIGITAL-exclusive enhancements include a Winchester disk backup/restore utility (BACKUP.EXE), a utility (RDCPM) to read CP/M-86/80 files, a loadable driver (MDRIVE) for using extended memory as a pseudo-disk, and support for IBM single-sided diskettes. Performance improvements encompass an optimized media check algorithm, increased sector buffers, and faster terminal I/O.

The system requires a Rainbow 100 computer with at least 128KB of memory, a dual-drive floppy diskette unit, a VR201-A Monitor, and a PC1K1-AA System kit with keyboard. The software is customer-installed, comes with a limited warranty, and offers optional support services like Telephone Advisory Service and Full System Service. The document also details the software license agreement, outlining terms of use, copying, and transfer.