[GreenKeys] WBR70

[David I. Emery]

On Fri, Oct 01, 2010 at 11:10:46PM -0500, David Christ wrote:
> Ah yes.  Reminds me of the high speed Shepard line printer we had 
> prior to 1970.  Had a rotating drum 132 characters wide engraved with 
> the alphabet and special characters.  132 hammers all driven by 
> discrete electronics supposed to hit the right letter as it came by. 
> No integrated circuits then!  Getting it to print the right letters 
> was bad enough.  Keeping it from printing wavy lines was well nigh 
> impossible.  Then we went to IBM printers with print chains.  Never 
> had to work on those.

	By the time I met the surplus Kleinschmidts I had long used Data
Products drum line printers to print software listings at work.   We had
one the size approximately of a VW beetle (or so it seemed) that zipped
out listings at speeds that would have qualified them for a speeding
ticket in some places.   Went through big boxes of fan fold paper heavy
enough to be hard for one man to lift - in an hour or so when going full
tilt.

	Drum printers (I think invented by a company called Anadex IIRC)
were extremely common on computers in that era... it was only later
after the infamous Centronix (origin of the original parallel printer
port interface) company came out with fast dot matrix printers that they
had much competition for high speed printers on computers (except
perhaps IBM chain printers).

	I did see the remains of pre IC drum printers occasionally in
surplus in that era... but never used or ever tried to repair one. I do
believe the very earliest were built in the vacuum tube era and the
electronics no doubt filled a reasonable room...

	Paper jams on a fast printer were a delight... could fill a
trash barrel with big wads of scrap paper in literally seconds...


> PS  Anyone have a CK722 in their junkbox?

	Probably - out in the junk in the back of the barn... doubt it
works any more, however...


-- 
  Dave Emery N1PRE/AE, die at dieconsulting.com  DIE Consulting, Weston, Mass 02493
"An empty zombie mind with a forlorn barely readable weatherbeaten
'For Rent' sign still vainly flapping outside on the weed encrusted pole - in 
celebration of what could have been, but wasn't and is not to be now either."