12 Jun
2004
12 Jun
'04
8:07 p.m.
Hi,
ard(a)p850ug1.demon.co.uk (Tony Duell) said:
UK PAL video equipment used to use a glass delay line as part of the PAL
decoder. This was a 'mechanical' device -- piezo-electric transducers
sent a pulse through the glass which was picked up about 64us (a little
less -- just under 1 line time) later by a similar transducers. Old VCRS
-- the better ones anyway -- used a 64us (exactly 1 line time) delay line
to store a video line to be used if there was a dropout on the tape.
Modern ones don't seem to bother :-(
I have often wondered about using such delay lines for data storage...
Or building a replica EDSAC??
--
Cheers,
Stan Barr stanb(a)dial.pipex.com
The future was never like this!