[Novalug] [OT] holy hair dryer

James Ewing Cottrell III JECottrell3@Comcast.NET
Thu Jun 25 21:32:19 EDT 2015


On 6/17/2015 12:16 PM, Beartooth via Novalug wrote:
> On Wed, 17 Jun 2015, Roy Wilson via Novalug wrote:
>
>>  Wow, that's a blast from the past.  I haven't needed to pre-heat a
>> transformer since the HeathKit days.  It used to be quite common,
>> especially with home-built electronics.  Just be happy you don't have to
>> give it high voltage to pre-heat the tubes. :)
>> **********************************************************************
>
>      Tubes?? There were PCs before the transistor??
>

Computers running on Tubes aren't as old as you might think. I went to 
UMD from 72 thru 76, and while I was there, we still had some IBMs (the 
model number matched the regexp "70?9?4?" (or maybe not)) that still ran 
on tubes. I never saw them; I ran on the "modern" Univac 1100 series, a 
one's complement, 2**18 36-bit word with 6-bit FIELDATA (with a mod that 
allowed 4 x 9-bit ASCII (which was rarely used)) characters, fed by 
punched card batch jobs on time shared with 110 baud (with TWO Stop 
Bits) ASR 33 Teletypes and later, a few "glass TTYs" locked away in the 
Graduate Labs and the Systems Staff, where I worked.

Come to think of it...that WAS awhile back. Still, it wasn't the 40s, 
50s, or 60s.

JIM



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