15 Feb
2008
15 Feb
'08
8:32 a.m.
Well, the types that I have listed are
Noval/Miniature types and date from
the fifties (the E180CC for example is the same as a 7062). These types
were specifically made for computers and haven't existed during WW2
The radar (mostly IFF) application predates computers. It became clear
in World War 2 that the standard line of tubes was sometimes suffering
problems with pulse recovery. There were plans to give IFF systems
real digital codes (even ciphered), but these just could not be made
reliably until a new line of tubes came out. These IFF systems came to
become the Mk X system with SIF (the octal code still in use today) in
the very early 1950s.
According to your logic one has to call the E180CC an
HiFi audio tube
because everyone's using them as such nowadays.
I never said that. Nor implied it.
I think we have to
differentiate between "computer tubes" as "tubes that were used in
computers but not specifically made for computers" and "computer tubes"
as
"tubes specifically made for computers/digital applications". I am talking
of the latter.
There really is no difference. Many of the radar types found their way
into computers, and vice versa. The digital application is the
significance. My point is that the thing that pushed the industry to
make these tubes is the military radar industry, not the computer
industry. I would bet that the number of sockets for "computer tubes"
in the 1950s for radar applications was thousands of times larger than
the number of sockets for computers.
Another example: The Zuse Z22 uses PL36 (or PL81?)
for IIRC core memory
drivers. This tube is actually a TV horizontal output tube and although
extensively used in a computer, was definitely not a "computer tube". But
the Z22 also uses logic modules with E92CC (7 pin dual triode, Green
Series).
There are all sorts of places in tube computers where odd tubes were
used. And vice versa, again.
--
Will