Functional Changes to the PDP-10 Architecture

This memo from Mike Uhler (dated 28 March 1983) addresses the need for a more disciplined process regarding functional changes to the PDP-10 architecture, specifically for the upcoming Jupiter II CPU hardware design.

Key points include: - Acknowledgment of previous lax documentation and ambiguous change processes. - Definition of the baseline functional description, which includes the Processor Reference Manual (AA-H391A-TK with updates) and KCIO version 8 (including the Extended Addressing chapter). - Establishing a deadline of 29 April 1983 for submitting proposed changes for the Jupiter II implementation. - Requirements for submissions, including Architecture Committee approval, a complete functional specification (covering normal and exception handling), and discussion minutes to avoid future ambiguity. - A warning that because hardware is more difficult to modify than microcode, the cost of post-design architecture changes will be high.