24x80 Standard? (was: Re: HX20)

From: Hans Franke <Hans.Franke_at_mch20.sbs.de>
Date: Tue Dec 15 07:23:28 1998

> I wrote:
> > No. I've seen 64-column text on typical mid-70s NTSC televisions, and it was
> > abysmal. The televisions had to be modified to remove their color trap
> > in order to get reasonably sharp characters.

> Hans replied:
> > (Please, notice, I havn't talked about Colour TV)

> > First, basicly 70's tv had the same specs than todays.

> No. Modern TVs have *much* better Y/C separation. Even the sets without comb
> filters still are better than the mid-70s sets. And the luminance bandwidth
> of modern TVs is much improved. We're comparing average televisions from the
> mid 70s and present, not top-of-the-line models.

Please, I'm _NOT_ talking about the TV sets, I'm talking about
TV specs - the standards about the TV signal - and they haven't
changed for the basic B&W and colour signaly since the 70s.

> [...]
> Besides which, mid-70s TVs, monochrome or not, simply were not designed for
> the horizontal bandwidth needed for good text display.

That has nothing to do with bandwide of the TV set - they where
able to work on and display the frequencies defined for TV, and
these are the limits - not the TV set - Even in the early 70's
B&W TV tubes and electronics where already better than needed
for the TV signal.

But if the signal definition doesn't allow a frequency high
enough for 80 columne display, no TV, not a 500 Mark nor a
10,000 Mark TV can display it. No cheap one from 1970 and
no SuperDuperHighThingy TV from 1998. You just can't stick
a 10 MHz signal within a 5 MHz chanal. The TV modulation
prohibits this.

> Apple's choice of a 40-column display was entirely correct given that they
> were originally marketing it to people who would use it with a television.
> Inexpensive video monitors weren't yet available. Of my friends who bought
> Apple ][ computers in the 1977 time frame, over half used the computer with
> a television. Most of the rest used Sanyo 9-inch or 12-inch monochrome
> monitors, and only a few used color monitors.

I did the same - my first display on the Apple][ was a 1968
build B&W TV (our old family TV, I got it in 1975 after we
had our first colour TV).

> IIRC, the Sanyo 9-inch monochrome monitor cost over $300 in 1977.

Jep, the prices have been around this in Germany. A friend of
mine was lucky - he dumpster dived a scraped 13" survilanve
Monitor - The best screen in the neighborhood.


Ich denke, also bin ich, also gut
Received on Tue Dec 15 1998 - 07:23:28 GMT

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