🚀 go-pugleaf

In article <1679@milton.acs.washington.edu> pingpong@milton.acs.washington.edu (jimmy) writes:

   >How difficult is it to build a NTSC <-> PAL device? (Any commercially
   >available ones?)

In the days before cheap digital memory it was done by an "optical" converter
(i.e. a high linearity monitor and a camera! ).
In the mid 70's the BBC produced ACE and the IBA produced DICE (Digital Inter-
continental Conversion Equipment). Both in the UK. 
Marconi sold DICE under licence to the IBA and McMichael/GEC sold ACE. The
TV station I used to work for bought a DICE in 1978 for $800,000. (When
an Australian dollar was worth $1.10 US.)

Cheap memory and LSI (DICE used mos shift registers) have made converters
cheaper. I think you could pick up a cheap one for about US$30,000.
Mind you the result looks cheap! The main difficulty in conversion is the
50 to 60Hz conversion. To do the temporal filtering properly you need at
least 4 fields of memory and good motion interpolation algorithms.

   >(I have a PAL VCR and a NTSC TV.)
   >Or would it be cheaper to buy a PAL TV?
   >

I think it would be cheaper to get a pal TV!

If you were trying to look at an NTSC picture on a PAL set its a different
story!
All you would need to do is to adjust the scans, defeat the PAL 7.8Khz switch,
and tweek the colour matrix resistors. We did this on some sets and we even
put in a circuit that detected the PAL burst and switched the monitor
automatically.


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