🚀 go-pugleaf

In article <1992Nov17.113157.12225@waikato.ac.nz>, ldo@waikato.ac.nz (Lawrence D'Oliveiro, Waikato University) writes:
> In article <Bxn4Jt.K2p@rahul.net>, jonathan@rahul.net (Jonathan Heiliger) writes:
>> In article <1992Nov12.190043.1@mars.slu.edu> jesse@mars.slu.edu writes:
>>
>>>What is the resolution of normal NTSC TVs?
>>
>>    NTSC is an analog format with a total of 525 lines.  However only 485 lines
>> are active.  The most universal is about 648x485 pixels;
> 
> Most video digitizers I've come across seem to prefer to give you 640*480
> resolution when grabbing frames from an NTSC source. I guess they're just
> rounding it to a more convenient number. Or perhaps there's some standard
> allowance in there for overscan.
> 
>> and NTSC cycles at approximately 59.94Hz.
> 
> I heard that the original black-and-white NTSC was 60Hz, and that the frame
> rate was lowered slightly to accommodate the colour signal--probably a question
> of avoiding interference between integer multiples of different frequencies.
> 
> Lawrence D'Oliveiro                       fone: +64-7-856-2889
> Computer Services Dept                     fax: +64-7-838-4066
> University of Waikato            electric mail: ldo@waikato.ac.nz
> Hamilton, New Zealand    37^ 47' 26" S, 175^ 19' 7" E, GMT+13:00
Truevision with their TARGA series pretty much set a defact frame grabber
standard early on. 512x480 is full screen and there is a lessor mode for a 
black box around the video. Even 512x480 offers more than NTSC resolution when
the capture is in 24bit colour.

Don
djlewis@ualr.edu