CDC 6600 display character generation

[Paul Koning]

> On Jun 6, 2018, at 3:40 PM, Chuck Guzis via cctalk <cctalk at classiccmp.org> wrote:
> 
> One of the more interesting things about the DD60 display was the use of
> 2C43 "Lighthouse" UHF triode tubes to drive the CRT electrostatic
> deflection.

UHF, yes, but not those.  The final state uses 3CX100A5 UHF transmitter tubes.  The 2C43 would not appreciate the 2000 volt plate voltage used in that stage.  The driver stages are fairly ordinary looking receiver style dual-triode tubes.

> Only being around briefly for the 170 system, I don't know how the
> magnetic deflection was driven there.
> 
> I imagine that the cost of the DD60 was due in no small port by the use
> of the CRTs--I believe they were produced in Germany.

Really?  It is shown as a K2263-P31, manufacturer Fairchild Camera and Instrument Corporation, Defense Products Div., Clifton NJ.  I sure would like to get my hands on specs for that tube.

In any case, they were sometimes referred to as "radar tubes" which sounds somewhat reasonable.  Certainly very different from TV CRTs, and bigger than what's used in oscilloscopes, so they were most likely low volume which would explain a high price.

	paul