15 Feb
2017
15 Feb
'17
11:28 p.m.
-----Original Message-----
From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Tony Duell
Sent: 16 February 2017 06:29
To: General Discussion: On-Topic and Off-Topic Posts
<cctalk at classiccmp.org>
Subject: Re: New batch of pdp8 OMNIBUS to USB interface! Please Read and
react!
were
Yes RTTY is de-facto 5-bit. I have never heard plain ASCII being used on-air. In its day
AMTOR which uses 5-bit codes and adds error was also popular. The most common ASCII modes
were AX25 and TCPIP over AX25.
and 5 bit
stuff almost unheard-of.
In the US, common for hams, not common for computers. Maybe they common for computers in the early 1960s.
I think at one time radio amateurs (at least over here) had to use 5 bit ITA2
machines for RTTY. It may even be to this day that RTTY implies that, and that
ASCII is classed as 'data'. But the 5 level machines that were used over here
tend to be Creeds (Creed 7s, 75s and 444s mostly).
I think it depends on "when". When RTTY first started Creed 7Bs were common
cheap and had governed motors so could be adjusted to run on 45.5 or 50 baud.
Later on 75's (which is my favourite) started to become available but many of these
had synchronous motors so could not be adjusted.
Finally 444's became available. I really don't like the 444 much. The typewriter
style type basket seems to be a backward step over the neat single element of the 75...
I used a 7B with my "Newbear 7768" 6800 system.
The RSGB (Radio Society of Great Britain, a bit like
the ARRL) 'Teleprinter
Handbook' (on RTTY operation) does have some details of things like the
Teletype 28, so I guess some made it over here, but I've yet to see one.
I have seen a couple of 28s crop up on E-Bay and I am sure I have seen one "in the
flesh" in some museum..
OK, we do see BRPE
punches from time to time.
I'd really like to get one of those!