[TUHS] lowercase vs. uppercase PDP-7?

Doug McIlroy doug at cs.dartmouth.edu
Mon Oct 7 03:47:47 AEST 2019

> The scans for v0 code are in lowercase. I assume printed on TTY 37.
> But why is the early PDP-7 code in lowercase?

Once you've used a device with lower case, upper case looks as
offensive as a ransom note. I went through this in moving "up"
from Whirlwind to IBM's 704. By 1969, we'd all had lower-case
terminals in our homes for several years.

So Unix was ASCII from the start. Upper-case from a TTY 33 was converted
to lower. On the PDP-11, at least, there was an escape convention for
upper case. I believe the lower-case convention was explained in the
introduction. In particular if you logged in with an upper-case user
name, the terminal driver was set to convert everything to lower.

Remember, too, that 33's used yellow paper. For printing on white
we had use other machines that had full ASCII support.


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