[GreenKeys] RCA teleprinter ad on EBAY 381052171359 trans-atlantic

[Jones, Douglas W]

On Nov 14, 2014, at 2:13 PM, Jim Haynes wrote:

> Teletype had a bidirectional tape reader circa 1959 that was used in
> the so-called Delta ASR set, the switching system for Delta Airlines.

I have two substantially identical Tally 424 paper-tape readers
(one partially cannibalized for parts), substantially identical
to the machine described in U.S.Patent 2,948,161 which has a
filing date of May 18, 1959.

See
-- http://www.cs.uiowa.edu/~jones/pdp8/UI-8/guide.shtml#unknown2
for photos, links to the patent, and pointers to the manual.
The bug list (linked from the above) indexes all of the work
we've done to restore this -- so far.  There are more photos
in the bug list and more in the repair log entries it indexes.

This is a bidirectional reel-to-reel paper-tape reader, with a
single drive motor and a dismaying number of differentials
inside, used to translate continuous motion from the motor into
incremental leftward or rightward tape motion and into feedback
controlled torque on the left and right reels.

Our drive has no coil on the reverse step pawl, so it can only
step forward.  It must have been manufactured that way as a
forward-only variant of a drive that was able to go both ways.
Leaving off this coil, while retaining the full complexity of
the bidirectional gearing and the mechanism of the reverse
pawl seems like it would have had very little effect on the
price.

		Doug Jones
		jones at cs.uiowa.edu