Comment by cm2187

2 days ago

You assume that non interlaced computer screens in the mid 90s were 60Hz. I wish they were. I was using Apple displays and those were definitely 30Hz.

4 comments

cm2187

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LocalH  2 days ago

Which Apple displays were you using that ran at 30Hz? Apple I, II, III, Macintosh series, all ran at 60Hz standard.

Even interlaced displays were still running at 60Hz, just with a half-line offset to fill in the gaps with image.

  • cm2187  2 days ago

    I think you are right, I had the LC III and Performa 630 specifically in mind. For some reason I remember they were 30Hz but everthing I find googling it suggest they were 66Hz (both video card and screen refresh).

    That being said they were horrible on the eyes, and I think I only got comfortable when 100Hz+ CRT screens started being common. It is just that the threshold for comfort is higher than I remember it, which explains why I didn't feel any better in front of a CRT TV.

    • LargoLasskhyfv  6 hours ago

      Could it be that you were on 60Hz AC at the times? That is near enough to produce something called a "Schwebung" when artificial lighting is used. Especially when using flourescent lamps like they were common in offices. They need to be "phasenkompensiert" (phase compensated?/balanced), meaning they have to be on a different phase of the mains electricity, than the computer screens are on. Otherwise even not so sensitive people notice that as interference/sort of flickering. Happens less when you are on 50Hz AC, and the screens run at 60Hz, but with flourescents on the same phase it can still be noticeable.