PoseidonTermServerSwSpec Oct84

This document is a Component Product Specification (Version 4.0, dated 17-Oct-84) for the POSEIDON Terminal Server Software, issued by Digital Equipment Corporation and marked COMPANY CONFIDENTIAL.

Purpose: It serves as the definitive description of the proposed goals, capabilities, and external characteristics of the POSEIDON Terminal Server, representing the agreed-upon commitment for "WHAT IS TO BE BUILT."

Key Features and Capabilities:

1. Functionality: POSEIDON is a high-performance, low-cost terminal server designed to connect up to eight asynchronous terminals to host systems on an Ethernet-based Local Area Network (LAT).
2. Architecture: It implements the Local Area Transport (LAT) architecture between the server and host. The operational software is downline loaded from a VAX/VMS system (running DECnet/VAX) into the POSEIDON hardware (based on a 10 MHz 68000 microprocessor). Low-level Ethernet maintenance is handled by ROM-based microcode.
3. User Interfaces:
   • Local Mode: Allows terminal users to connect/disconnect from hosts, set/show terminal parameters, and display host information. Includes an Autobaud feature for automatic speed detection.
   • Privileged Local Mode: Provides Terminal Managers with password-protected access to configure server parameters, perform Ethernet maintenance functions (e.g., Loop Server, Loop Requester tests), use an Online Debugging Tool (ODT) for diagnostics, and initiate software resets.
   • Host Mode: Enables communication between the terminal user and an authorized host system.
4. Terminal and Modem Support: Supports various asynchronous ASCII terminals (e.g., DEC VT and LA series) and terminal emulation modes (e.g., RAINBOW-100), with line speeds from 50 to 19200 bps (line mode) or 9600 bps (block mode). It conforms to DEC Standard 052 for modem control (EIA RS-232C and CCITT V.24 standards).
5. Security: Features password protection for access to POSEIDON functions.
6. Reliability & Maintenance: Categorizes error types and defines reliability goals for release. Maintenance is customer-installable, with software updates provided via "Autopatch kits." It supports upline dumps for crash analysis.
7. Performance Goals: Aims to achieve full-duplex I/O at 9600 bps across all terminals and minimize host CPU utilization compared to traditional interfaces.
8. Compatibility: Designed to be compatible with other LAT-based terminal servers and adhere to Ethernet Version 2.0 and Digital NI node architecture specifications.
9. Publications & Cost: Supported by a User's Card, Operations Guide, and Software Installation Guide. The non-modem version is projected to cost around $500, and the modem control version around $600.
10. Development Constraints: Mentions memory utilization and execution speed as key constraints, acknowledging that certain features (like an undocumented MONITOR command or VT100 escape sequences in local mode) might be sacrificed if memory limits are not met.

The document also includes detailed sections on message formats, memory layout, state tables, and a list of outstanding issues to be defined later.