TC <do-not-reply@i-do get-enough-spam-already-2498.com> wrote:
> Well, I do not know how old you are, but everything was SLOW back then.

  I don't think a computer has ever existed where plotting n pixels, where
n is the width of the screen, takes 10 minutes (well, at least if we are
talking about computers which had a TV/monitor screen output). I would be
surprised if it took even 10 seconds in any such computer, even if you were
to plot *all* the pixels on screen individually (not just one pixel per
column).

  After all, these computers were used for playing games, editing text,
programming and so on. They would be completely *unusable* if it took
minutes to draw a screenful.

  Calculating a sine wave might take some time in a really old computer,
but still nowhere near 10 minutes. 10 seconds I could believe with a 70's
computer. Maybe.

> Even 
> accessing memory locations using peek and poke did take some time.

> http://en.wikipedia.org/wiki/Commodore_VIC-20

  This computer was used to play games. Are you telling me it took 10 minutes
to update each frame? Or even 10 seconds?

  I bet the framerate was probably more along the lines of 10 frames/s, if
not even faster.

  (Yes, I know that in many old computers and game consoles drawing one
single pixel was much slower than drawing a hardware-supported sprite, but
I am still unwilling to believe the 10-minute claim. Even 10 seconds sounds
absurd, even if you are filling the entire screen.)

> Back then you tried everything to increase speed. Instead of dividing by pi 
> you manually computed 1/pi and used this as a factor (muliplication was way 
> faster than division), instead of using x^2 you used x*x (faster ;-), I 
> think you get the picture. But if you did not experience this first hand, 
> you will not believe it.

  I think that it's you who is far, far off. You make it sound that those
old processors supported floating point numbers or even multiplication in
the first place. Most of the old CPUs back then (eg. the Zilog Z80, which
was rather popular and used in many home computers) didn't support even
integer multiplication, much less floating point.

  But even if you had to perform integer multiplication in software, it
would still not have taken anywhere in the range of minutes to fill up
a screen of pixels (unless calculating each pixel was heavy; eg. drawing
the Mandelbrot set back then could take hours, but not because it was slow
to draw, but because it's immensely slow to calculate).

-- 
                                                          - Warp

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