24x80 Standard? (was: Re: HX20)

From: Eric Smith <eric_at_brouhaha.com>
Date: Mon Dec 14 18:19:11 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.

Even monochrome monitors had the color trap, which is what prevented
legible text display of much more than 64 columns. And usually it was a
low-pass filter, rather than a notch filter. It never was a comb filter.

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

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.

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

Eric
Received on Mon Dec 14 1998 - 18:19:11 GMT