Computer in 1900, was RE: Oldest operational computer was Re: cctalk Digest , Vol 54, Issue
Roy J. Tellason
rtellason at verizon.net
Sat Feb 16 00:22:41 CST 2008
On Friday 15 February 2008 10:48, William Donzelli wrote:
> > I seem to recall that this was about the biggest problem in getting
> > Colossus to work in the 1940s; the technology for doing the optical
> > detection of the tape data just wasn't really 'there' yet, not at any
> > speed. I think the maximum they managed to get was around 8KHz, but it
> > wasn't particularly reliable (I think 5KHz was the norm, and it took an
> > awful lot of initial effort to get that working properly).
> I am not sure what the photocells of 1920 were up to, but by 1940 they
> were not half bad, with so many being used for FAX service. 8 KHz may
> be about right for off the shelf tubes.
For some reason when I read "photocell" earlier on in this thread I started
thinking about CdS and similar stuff, not thinking about _tubes_ per se,
until I hit the last paragraph of this post...
There are a number of different photocell datasheets on my tubes page:
Perhaps this info might be useful Some of those real early audio and other
tubes are in there too, though I don't recall offhand if that stuff is dated
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, a critter that can
be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters"
Information is more dangerous than cannon to a society ruled by lies. --James
More information about the cctalk