Quote:
Originally Posted by j.p.s
Well, if you're going back 40 years and more, there's flyback transformer whine, crude low resolution fonts, huge gaps between scan lines, and gaps between pixels. The first one was particularly bad (beyond headaches) for some pregnant users.
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Transformer whine was approx 10 kHz on 405 TV and about 15 kHz on 525 or 625.
Progressive VGA and higher was a minimum of about 31 kHz, which no-one can hear.
The poor screen resolution (IBM Mono and old terminal monitors) was poor aesthetics rather than headache inducing. By 1980 (before IBM PC came out) one conclusion was reflections and the other less supported by science was to use green or brown phosphor instead of white (as used on TVs). We made monitors for Apple II, Acorn/BBC and Research Machine 380z, mostly mono with brown or green CRTs, but some colour sets, all based on Thorn 625 line TV chassis. The coloured phosphor was for market demand and gave us the edge of those selling white phosphor Hitachi security monitors. The mono screens were not matt but less shiney than the mono TV CRTs, or the later official IBM CGA (whine) and EGA (no whine).
Though 15.625 kHz, our monitors had no transformer whine in 1980-1983. The whine would have been older terminals. The 405 TV in all of UK from 1935 to 1985 with 1939-1946 gap (and parts of Ireland 1962-1985) was bad for line frequency whine of 10.125 kHz (mostly from scan coils but paritially the LOPT).
The ACT Sirius 1 (Victor 9000) was in UK before IBM PC in 1981 and had a true matt screen due to a mesh on the front. Later there were similar meshes sold to clip on. I have one in the attic from a 1980s terminal. By mid 1980s there were some screens with matt surface to the glass or faceplate as the mesh system was no use for higher resolution displays.