Font type and size was (QVGA V/s VGA for GTA03)

Hans L thehans at
Tue Jun 17 07:17:51 CEST 2008

On Tue, Jun 10, 2008 at 8:59 PM, Dale Schumacher
<dale.schumacher at> wrote:
> If your current display is around 150dpi, you can see what QVGA would be
> like with something like this:
> xterm -fn '*-clean-*--6-*-c-40*' &
> This will give you a terminal window with a 4x6 font cell (3x5 for
> characters + 1px spacing).  Note that the automatic "smear bold" make this
> font unreadable, but the non-bold works.
> However, I would much prefer to use a larger font on a VGA-size display with
> 285dpi, like this:
> xterm -fn '*-clean-med*--16-*-c-80-*' -fb '*-clean-bold*--16-*-c-80-*' &

I think that in order to most accurately simulate the viewing
experience of a handheld device, ideally you want to show the same
number of pixels in a particular angle of view.
Since the pixels per inch of the GTA display are most likely not the
same as your computer monitor, you can adjust this effective angle of
view by changing your distance from your monitor.

After some wikipedia and a little arithmetic, I think that the
situation can be simplified to the following equation:

Dcm =  Dhh * PPIhh / PPIcm

Dcm = viewing distance of computer monitor
Dhh = viewing distance of hand-held device
PPIhh = Pixels Per Inch of hand-held device
PPIhh = Pixels Per Inch of computer monitor

I held up my current phone, as if I was about to type something on the
keypad, and determined that a comfortable position for me is to hold
my phone roughly 12" in front of my eyes.

The GTA02 device has 640 pixels along it's longest dimension of 2.27".
 640 / 2.27 is about 282 PPI
The monitor I'm using right now has 1024 pixels on its horizontal, and
is 12" wide, which comes to about 85 pixels per inch.

So, in order to simulate the GTA02 displaying VGA xterm at 12" viewing distance:

12" * 282ppi / 85ppi = about 40"

I can then view this command from 40" away from my monitor:
> xterm -fn '*-clean-med*--16-*-c-80-*' -fb '*-clean-bold*--16-*-c-80-*' &

...and it will theoretically take up the same field of view as a (VGA)
GTA02 at 12"

To compare with a same sized QVGA screen, view at half distance as
previous command(20" for me):
> xterm -fn '*-clean-*--6-*-c-40*' &

Disclaimer: I'm certainly no expert in visual perception or optics,
and even my geometry is a little rusty, so please correct me if any of
this doesn't make sense.

So, with the geeky number crunching out of the way, my conclusion to
this experiment is that I find that (my simulated version of) 640x480
on a 2.27" screen is very readable at 80x24, and very useful (to my
eyes anyways).

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