[GreenKeys] Dot Matrix Printers

[Chris Elmquist]

On Wednesday (12/07/2011 at 08:12PM -0600), Jim Haynes wrote:
> 
> see also http://juliepalooza.8m.com/sl/qwint.htm
> 
> for the Qwint teleprinter, made by a small company north of Chicago,
> which included at least one former Teletype person.

Interesting for sure.

I note this comment in the writeup,

	The acoustic coupler operated on a 780-series machine was capable
	of operating at 1200 baud, even over long distance phone lines. To
	the best of my knowledge, no other company ever made an acoustic
	coupler of this speed. This was amazing; the only catch was that
	both ends of the conversation had to be MNP (Microcom Networking
	Protocol) capable. Many modems were capable of MNP at that time,
	so this was not a problem.

There were many 1200 baud acoustic couplers actually.  AJ (Anderson-
Jacobson), Multi-Tech (where I worked), Vadic, Novation and others
made 1200 baud couplers.  Some were Bell 202 with a 1200 baud forward
channel (toward the terminal) and a 50 baud reverse channel operating
in duplex and others 1200 baud each way but operated in half-duplex.
The Control Data Plato system used duplex 202 acoustic couplers to hook
their terminals up to the Cyber mainframe over dialup circuits.

Chris

-- 
Chris Elmquist