21 Jan
2008
21 Jan
'08
9:41 a.m.
I never knew
that an ASR-33 had a bell like an old typewriter to
indicate that your near the end of the line. Funny! The computers
probably had a special microphone to hear it when printing a directory
listing :-)
I though the 'end of line' trigger for the bell was actually an option,
but that all Model 33s (RO, KSR, ASR) had the bell which was mechanically
triggered by a ^G character. Oh yes, the VT50 series of DEC terminals have a little
relay on the logic
board. It'spulsed to geenrate the keyclick and sent a square wave signal
to generate the 'bell' which sounds rather like a 'raspberry'.
-tony
Maybe I need to make a video of the VT52 with the ^G bell sound. It
is a strange sound. We used to write programs on the PDP-11 back in
the 70s to "ring the bell" under certain conditions (winning a game,
etc.).
Note on my videos that the VT05 (DEC's early video terminal) also
buzzes at the end of the line on long lines.
Ashley