|Re: HP-41C Video interface PAL/NTSC?|
Message #4 Posted by Diego Diaz on 6 Nov 2003, 4:49 a.m.,
in response to message #3 by Giuseppe Marullo
I don't think you must care about this. As for early 80's TV sets were designed to handle one specific system PAL, SECAM, NTSC... but remember those are colour modulation system, so the colour information in the composite video signal becomes useless from one system to the others. But colour is not an issue with HP-41 system, as they only offer B&W.
Next thing to care is luminance (the real B&W image), and again, nothing to care about, signals are compatible at this level.
Synchronism is the last point, PAL uses 625 interlaced horizontal lines and 50Hz vertical refresh rate, while NTSC handles 525 interlaced lines and 60Hz vertical refresh... This sound quite different, but they aren't. In fact almost every TV set manufactured since early 90's handles both systems efficiently.
So you can symply plug it into your TV set video input (usually an RCA type coaxial connector) or to the V-IN line if you are going to use an Euroconnector (Scart).
The signal itself is a composite 1Volt peak to peak assymetric video. Video info goes from 0 to +0.7v while sync pulses go from 0 to -0.3v.
Anyhow, you must be carefull if you are intended to use an old B&W monitor, as those are usually suitable for one specific video system.
Hope this help