FCO DSRVD-0001 (DAS), DECserver 90L errors & slow echoing chars

This Field Change Order (FCO DSRVD-0001) outlines an upgrade for the DECserver 90L (DSRVD) terminal server, targeting U.S. Digital Assisted Service Customers. The FCO addresses two critical problems with DSRVD firmware versions below Revision Level "A": the premature stopping of terminal and printer sessions (often accompanied by "%DS90L-311 Illegal Message" or "%DS90L-323 Protocol Error-Invalid Slot Received" errors) and unacceptably slow character echoing for terminal users connected to VAX4000 systems.

The solution involves replacing the existing DSRVD modules with a DSRVD-M Terminal Server Module. The document provides a step-by-step installation and testing procedure, which includes logically and physically removing the DSRVD from the network, installing the new upgrade module, reapplying power, and verifying its functionality using front-panel LED indicators. These checks confirm power reception, successful self-test, network connection, and active port communication.