2 ms·

Most people are too young to remember that when you typed your username in all-caps in the login prompt (because the CapsLock key was on by accident, for exampl

by zvr 2y ago

Most people are too young to remember that when you typed your username in all-caps in the login prompt (because the CapsLock key was on by accident, for example), the login(8) program assumed you were in a connection that could only do 7-bit (upper case, but no lower case characters) and immediately switched the tty settings and you were then presented with a "\PASSWORD: " prompt.

roelschroeven 2y ago
Don't you mean 6-bit? 7-bit ASCII supports lower case characters. Or maybe there are other 7-bit character sets that don't have lower case characters and it was one of those?
- jks 2y ago
  PETSCII? On the Commodore 64 you could press the Commodore key and Shift together to change character sets between lowercase and the graphical characters. But the Unix login thing might have been because of teletypes? https://www.columbia.edu/cu/computinghistory/teletype/ https://www.columbia.edu/cu/computinghistory/teletype/ claims that ASR 33 used 8-bit ASCII but was uppercase only - not sure if the "8-bit" claim can be true. On some Unix (and Linux) systems, you can still enter a kind of retro mode with "stty olcuc iuclc" (output lowercase to uppercase, input uppercase to lowercase) and turning on Caps Lock.
- zvr 2y ago
  You are of course correct that 7-bit ASCII includes lower case characters. I don't think there exists "6-bit ASCII", but the original ASCII did not have lower case (the slots were empty). We're talking early '60s here. I'm not even sure it was only about ASCII. I suppose I should have written a more generic "character set" (which supports or not lower case characters) rather than "7-bit". In the cases where you could only communicate in a single case (upper), you typed the commands in the usual letters (e.g., "LS") and capital letters were designated by a preceding backslash (e.g., "ECHO \JOHN \DOE"). That's why you were seeing the "\PASSWORD: " prompt, the initial letter was capital (as it still is). Just for fun, I checked my current Debian system. The getty(8) command still supports it: -U, --detect-case Turn on support for detecting an uppercase-only terminal. This setting will detect a login name containing only capitals as indicating an uppercase-only terminal and turn on some upper-to-lower case conversions. Note that this has no support for any Unicode characters.

by zvr 2y ago

roelschroeven 2y ago

Don't you mean 6-bit? 7-bit ASCII supports lower case characters. Or maybe there are other 7-bit character sets that don't have lower case characters and it was one of those?

jks 2y ago
PETSCII? On the Commodore 64 you could press the Commodore key and Shift together to change character sets between lowercase and the graphical characters. But the Unix login thing might have been because of teletypes? https://www.columbia.edu/cu/computinghistory/teletype/ https://www.columbia.edu/cu/computinghistory/teletype/ claims that ASR 33 used 8-bit ASCII but was uppercase only - not sure if the "8-bit" claim can be true. On some Unix (and Linux) systems, you can still enter a kind of retro mode with "stty olcuc iuclc" (output lowercase to uppercase, input uppercase to lowercase) and turning on Caps Lock.
zvr 2y ago
You are of course correct that 7-bit ASCII includes lower case characters. I don't think there exists "6-bit ASCII", but the original ASCII did not have lower case (the slots were empty). We're talking early '60s here. I'm not even sure it was only about ASCII. I suppose I should have written a more generic "character set" (which supports or not lower case characters) rather than "7-bit". In the cases where you could only communicate in a single case (upper), you typed the commands in the usual letters (e.g., "LS") and capital letters were designated by a preceding backslash (e.g., "ECHO \JOHN \DOE"). That's why you were seeing the "\PASSWORD: " prompt, the initial letter was capital (as it still is). Just for fun, I checked my current Debian system. The getty(8) command still supports it: -U, --detect-case Turn on support for detecting an uppercase-only terminal. This setting will detect a login name containing only capitals as indicating an uppercase-only terminal and turn on some upper-to-lower case conversions. Note that this has no support for any Unicode characters.