Provide more sources and reword some sections.

readme.rst

@@ -366,23 +366,30 @@ Unix was case-sensitive because Multics was case-sensitive.
 Multics was case-sensitive because the ASCII standard
 included both an uppercase and a lowercase alphabet. [#Multics_case_sensitive]_
 
-Why was ASCII case-sensitive?
-It nearly wasn't.
+Why did ASCII do this?
+It was a close call, and almost didn't happen.
+
+Telegraphy codes used uppercase only,
+or at least did not distinguish upper and lowercase.
+Even ITA2, an international standard from 1930,
+used a 5-bit code with a shift to switch between letters and figures,
+but not upper and lowercase. [#ITA2]_
+Similarly, punched cards used uppercase letters only.
 
-Early telegraphy codes did not distinguish upper and lowercase
-because it would have slowed transmission speeds prohibitively.
 Encodings with different bit patterns for uppercase and lowercase
 had been proposed as early as 1959, [#Bemer_1959]_
 though they were not widely implemented.
 For example, the IBM 7030 "Stretch" supercomputer used an 8-bit encoding
 that included interleaved uppercase and lowercase alphabets,
-and it was used at Los Alamos in 1961.
+and was used at Los Alamos as early as 1961.
 [#Stretch_supercomputer]_
 
-The ASCII committee concluded that 6-bit encodings (64 bit patterns)
+Early on, ASCII committee concluded that 6-bit encodings (64 bit patterns)
 were insufficient to include both control characters and special characters
 in addition to the required 26 alphabetics and 10 numerics,
 so they decided to use a 7-bit code.
+However, ASCII was designed to include a useful 6-bit subset,
+which could only include single alphabet.
 
     The consideration of a 6-bit, 64-character graphic subset was important
     to the standards committee. If the ultimate decision was that columns 6
@@ -412,15 +419,22 @@ wanted to reserve the remaining space for control characters.
 
     --- Ibid, p.232
 
-Thought the comittee first formed in 1961,
-it wasn't until late 1963 that they finally agreed to include a lowercase alphabet.
+Though the comittee first formed in 1961,
+it wasn't until late 1963 that they finally agreed to include a lowercase alphabet,
+largely because of the influence of the
+International Telegraph and Telephone Consultative Committee (CCITT).
 
-    At the first meeting of ISO/TC97/SC@ in 1963 October 29-31, a resolu-
+    At the first meeting of ISO/TC97/SC2 in 1963 October 29-31, a resolu-
     tion was passed that the lower-case alphabet should be assigned to
     columns 6 and 7.
 
     --- Ibid, p. 246
 
+    The ISO proposal, though, did not include the lower case alphabet and the
+    five accent marks that the CCITT considered essential.
+
+    --- Eric Fisher, "The Evolution of Character Codes, 1874-1968", p.22
+
 Why is it useful for filenames to include upper and lowercase?
 
 It can make filenames more intelligible,
@@ -559,7 +573,22 @@ For example, the Linux port of the `Unity engine`_ has `issues with case-sensiti
        Everything in Multics is case sensitive; Multics permits use of the full
        upper and lower case ASCII character set.
 
-   http://www.multicians.org/mgc.html
+       Multics command names and programming languages use lowercase by
+       convention, but users are free to use uppercase letters in path names,
+       identifiers, user names, etc.
+
+   http://www.multicians.org/mgc.html#commandlanguage
+
+       Multics was one of the first systems to use upper and lower case letters
+       freely.
+
+   http://www.multicians.org/mga.html#ASCII
+
+       Obviously, BCD had no lower-case characters, and Multics did not use BCD
+       at all, except to output log and crash and tape mount messages from ring
+       0 to the primitive Selectric operator's console.
+
+   http://www.multicians.org/mgb.html#BCD
 
        Since the Multics file system distinguished between upper and lower case,
        external names had to be case sensitive, and without much discussion we
@@ -567,6 +596,14 @@ For example, the Linux port of the `Unity engine`_ has `issues with case-sensiti
 
    http://www.multicians.org/pl1.html
 
+.. [#ITA2]
+
+   See p. 9 of "The Evolution of Character Codes, 1874-1968", Eric Fisher.
+
+   http://trafficways.org/ascii/ascii.pdf
+
+   https://github.com/ericfischer/ascii
+
 .. [#Bemer_1959]
 
        Simple pattern of correspondence should exist between codes assigned to