|On page C-14 of a DEC manual (see below) there is a wonderfully obscure table. Here is the text that appears before the table:|
C.6 F40 UUO MNEMONICS
Table C-IO shows mnemonics that are defined only if MACRO is assembled
with the F40 switch on. These mnemonics generate UUOs, which are
handled properly if the program is running under control of the FORSE
F40 UUO Mnemonics"
The table contains thirteen mnemonics: ***DATA, ***FIN, ***IN, ***INF, ***MTOP, ***NLI, ***NLO, ***OUT, ***OUTF, ***RESET, ***RTB, ***SLIST. The manual does not document what those asterisk characters should be read as. In other words, the DEC authors assume that the reader will properly punch into their cards or paper tape UUONIF and not ***NIF. Understanding this table depends on massive knowledge not discussed, nor even alluded to. It also depends on understanding the typographic conventions that DEC uses in this manual.
What puzzles me is that "***NIF" and "UUONIF" contain *exactly* the same number of characters, and the author(s) are saving no ink nor the trouble of typing repeated characters. The author(s) are making the table needlessly obscure, since "***" is not what you punch into your paper tape. The author(s) would have been clearer and more precise if they had typed "UUO" in the place of "***" every time.
What was the engineering typographic style that would produce such text?
Does anyone know why they did it this way?
Was it some sort of in-group convention?
Were the author(s) were thinking, perhaps unconsciously, that only those who have read previous manuals for this company, and other computer companies, will get it, so if it confuses a reader that is because they are a newb. Newbs will have to ask their experienced supervisor, or colleagues, what it means.
I am delighted to be brought back to my roots. The first biochemistry lab I worked in had a PDP10.
The manual is:
This document describes the language elements
of the MACRO-10 Assembler for the DECsystem-10.
OPERATING SYSTEM AND VERSION:
This document supersedes the document
of the same name, Order No. DEC-10-LMCOA-B-D,
published July 1977
TOPS-10, Version 6.03
MACRO-10, Version 53