Poul-Henning Kamp wrote:
In message <4b251964.5040...@rubidium.dyndns.org>, Magnus Danielson writes:
Joe Gwinn wrote:
The exception to this was that video generators were (and still
are) often locked to the AC line so that hum bars would not drift across
the screen.
I have never seen this in any of the devices I've seen. It is certainly
not what we do in the TV world either. Examples would be good.
This feature disappeared with color television, specifically NTSC, which
tweaked the vertical frequency just a tad lower than 60Hz.
That ghastly horrible 1000/1001 factor which plauge us still today. The
PAL hack to the same problem has less withstanding effects. Whenever
they did the HDTV standard they failed to keep the number magic of
digital SDTV (i.e. 13,5 MHz and 18 MHz in BT.601). While that solution
solve the technical problem, they solved in a bad way and we still
stuffer even when the original reason for the solution have disappeared.
Poul-Henning
PS: But NTSC gave us the 14.31818181.. MHz frequency, as imortalized
by the ghastly colors of the IBM CGA.
Most people saw CGA using RGBI monitors, so I think it is a bit unfair
connection. Regardless, it was never the interface of precission
colours. Things got better when IBM used the INMOS G171 for the VGA LUT
and DAC.
Cheers,
Magnus
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