23 Nov
2017
23 Nov
'17
3:33 a.m.
On 23/11/17, Nigel Williams wrote:
On Thu, Nov 23, 2017 at 6:40 AM, Nigel Williams
<nw(a)retrocomputingtasmania.com> wrote:
I wrote a VT05 emulator some while ago: https://github.com/aap/vt05
It's certainly not perfect and probably has some bugs, but I somehow had
the urge to write it for no particular reason.
I would actually be interested in the newline delay the machine needs
because I didn't implement it.
I hope this doesn't derail the discussion too much, but I would actually
like to know which teletypes were used at bell labs. What strikes me as
odd is that in UNIX lower case is the norm yet the ASR-33, which I would
assume was ubiquitous, does only to upper case and also doesn't do some
characters used by C, like {}. In this famous photo you see ASR-33s...so
were they really the main interface to early UNIX?
https://www.bell-labs.com/usr/dmr/www/kd14.jpg
aap
I suspect the VT05 was not popular as it was
slow, uppercase only, 72
characters x 20 lines, and not cursor addressable (much like Teletypes
of that time).
I am wrong, DEC VT05 was cursor addressable, it could even erase to end of line.
3.8 Direct Cursor Addressing (CAD)
https://vt100.net/docs/vt05-rm/chapter3.html#S3.8
Through the use of CAD (0168), the cursor can be directed to any one
of the 1440 character locations on the CRT screen using three
instructions. The CAD function is used to allow updating of displayed
data without retransmitting the complete page. 