Firefox Workstation I/0 Cover Module Functional Specification

This document is the Functional Specification (Revision 1.2) for the Firefox Workstation I/O Cover Module (H3061), authored by Michael Nielsen of Digital Equipment Corporation on December 23, 1987.

The I/O Cover Module acts as an interface, connecting the internal Firefox Workstation I/O module (L2003) to external peripherals. It is a 5.2 x 8-inch, 4-layer printed circuit board assembly that features:

• External Connectors: For keyboard/mouse/tablet (15-pin D), modem (25-pin D), and printer/console (6-pin MMJ).
• Ethernet Connectivity: Supports both Thin Wire (BNC connector with integrated transceiver) and Thick Wire (15-pin D connector), with a switch to select between them.
• EIA Driver and Receivers: Implementations for serial communication lines, including ESD/EOS protection and specific voltage supplies (+/-10V).
• Power Supplies: Provides +5.3V, +12V, and a -10V (via a switchmode power supply) for external devices like keyboards, mice, and tablets.
• Hexadecimal-Digit Display: A single digit display for status outputs.
• Battery Backup: A 3.75V, 180 mAh nickel-cadmium battery to maintain the L2003's time-of-year clock and RAM during power failures.
• Internal Connection: Connects to the L2003 via a 50-conductor ribbon cable.

The specification also details pin assignments, power requirements (maximum 9.1 watts dissipation), and methods for error diagnosis using loopback connectors. The document is marked "RESTRICTED DISTRIBUTION" and includes a disclaimer stating that the information is subject to change and not a commitment to any current or future product.