Are UI developers all left handed?

Dale Amon amon at
Sat Aug 11 22:33:27 UTC 2012

On Thu, Aug 09, 2012 at 07:01:47AM +0200, David Klasinc wrote:
> >I can tell you the historical reasons. All windowing systems
> >began with their coordinate systems with 0,0 in the upper left
> >because that is where the scan lines begin. Lines are written
> >from left to right, top to bottom.
> Why the top left corner? I believe that even those historical
> reasons are there for a, hehe, reason.
> It has nothing to do with the hand movement and in which direction
> it is easier to move the mouse. Honestly, moving mouse to the left
> or to the right feels pretty much the same to me. We're moving a
> relatively small and light mouse, we're not rowing a boat.
> Focus is the key here. We are more focused on the top left corner
> because (most of us) read from left to right and from top to bottom.
> That is why putting everything in that corner is completely natural
> and most ergonomic.

The historical reasons have nothing to do with human factors and
everything to do with the details of an electron beam scan in a
CRT. Beams go left to right, flyback and scan lines go top to bottom
on each frame. All the electronics (remember these kind of units
were around when a large integrated circuit had an 8 bit shift
register and most were TTL 7400 series... I suspect some even
predated TTL. Characters were in hardware. There was one character
set. The origin was upper left, the origin of the electron beam

Now, perhaps someone can dig back into the 1930's or earlier and
find a reason for CRT's being left to right and top to bottom, but
in the time frames we are talking about it is simply that technology
builds on things that work and rarely is it worth the effort to
go back and redo decades of engineering from scratch.

You will always know that if you write to screen coordinate 0,0, it
will be visible. Anything beyond that is an unknown.

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