20 Feb
2013
20 Feb
'13
7:14 p.m.
On 2013 Feb 20, at 11:01 AM, Holger Veit wrote:
Am 20.02.2013 15:04, schrieb Allison:
According to the ref'd manual there is a 'Baudot'/5-level option. To
quote, page 21:
BAUDOT TELETYPE OPTION
The Baudot version of the PROM Monitor .. to support a Baudot
Teletype ..
and convert between Baudot (5-level code) and 7-bit ASCII.
The manual goes on to talk about the 5-bit character translations and
shows a layout of a simple 5-level teletype keyboard.
You guys are forgetting that one of the most affordable terminal/
consoles for the computer hobbyist in the Altair era was a 5-bit
teletype. They were obsolete and available as surplus. 8-bit ASR-33s
and the like were still current equipment and not cheap. If you were
lucky you might manage to get your hands on a 7-or-so-year-old
surplus video terminal for cheap. A current video terminal would be
another significant expense in addition to the computer.
And just because we're discussing 5-level teletypes, if someone wants
one I can supply you with one or more. Pickup Vancouver,B.C.,Canada
region.
On 02/20/2013 04:17 AM, Holger Veit wrote:
This was referred to in the listing as
"Baudot". You're right, this
is not 5 bit baudot/murray code. It is bit-banging tty, in contrast
to an ACIA, though.
What you have to set the terminal to depends on the jumper
settings on the board. It also depends on the monitor itself -
there is an ACIA version which can work with 9600 8n1, but there
is also a Baudot TTY version.
There is no baudot TTY option its a 20ma serial loop option
commonly used for the asr33. >> There is a listing of the monitor and VTL-2 at
http://
>> www.altair680kit.com/manuals/Altair_680-System_Monitor_Manual-03-
>> Beta_1-Searchable.pdf
>> (toplevel page http://www.altair680kit.com/manuals.html).