Software Product Description

The ULTRIX Operating System, Version 4.1, is Digital Equipment Corporation's native implementation of the UNIX® operating system, designed for VAX, MicroVAX, VAXstation, and Digital RISC systems. It functions as an interactive, demand-paged, virtual memory, multi-processor, time-sharing OS, offering a hierarchical file system, interprocess I/O, asynchronous processes, and high portability for applications. It builds upon Berkeley 4BSD functionality with Digital's own enhancements.

Key features and improvements include:

• Multiprocessor Support: The ULTRIX kernel is enhanced to support multiple VAX and RISC processors, utilizing semaphores and spin locks for synchronization and allowing control via startcpu and stopcpu commands.
• Data Management: Introduces ULTRIX/SQL, an industry-standard SQL relational database management system compliant with ANSI/ISO 9075:1989 (Level II) and offering portability with Rdb/VMS and IBM DB2. It features a multi-server architecture, intelligent query optimizer, and network access via DECnet and TCP/IP.
• System Administration: Enhancements include integral bad block replacement, system diagnostics, error logging, remote backup, network installation, and support for up to 256 simultaneous users.
• Communication: Provides extensive networking capabilities including Ethernet (TCP/IP, ThinWire, baseband, DECnet-ULTRIX), CI network support for host-to-host communication, LAT for terminal servers (up to 256 sessions), and an IBM 2780/3780 Terminal Emulator (VAX/MicroVAX only).
• Security: Designed to comply with C2 security levels (Orange Book, Green Book), offering memory/terminal protection, a Trusted Path facility, enhanced login/password functionality (shadow authentication, configurable policies), and a security auditing subsystem. It also integrates BIND V4.8, HESIOD name services, and Kerberos for authentication.
• Program Development: Offers various tools like VAX C/ULTRIX, portable C, Pascal, and Source Code Control System. The CDA Toolkit provides an object library for Compound Document Architecture (CDA) compliant applications, supporting revisable file format interchange and migration across different Digital OS platforms.
• Virtual Memory: Features full demand paging, System V memory extensions (shared memory, page locking), and backing store on local or NFS remote disks.
• User Interfaces: Supports common UNIX shells including C Shell, BSD Bourne Shell, System V Bourne Shell, and Korn Shell.
• Standards Compliance: Highly compliant with POSIX (IEEE 1003.1-1988, NIST FIPS 151-1), SVID Issue 2 Volume 1, and X/OPEN (XPG3 BASE level with upgrade). It also maintains compatibility with 4BSD, Sun NFS Version 2.0, and various UNIX commands.
• Internationalization: Includes a comprehensive Native Language System (NLS) supporting multiple languages (French, English, German) with character sets like MCS, ISO 8859/1, and ISO 646, along with tools for message catalog and codeset conversion.

ULTRIX 4.1 runs on a range of VAX, MicroVAX, and Digital RISC systems, with specific hardware configurations and memory requirements detailed. It supports diskless workstations and CI (Computer Interconnect) environments. Licensing is CPU-based, with options for user upgrades and optional encryption software subject to export regulations. Source code distribution is available under specific AT&T UNIX license conditions.