Paul,
You are right. 'f' and 'F' are the same. Lower case characters are
always a bit difficult. 'D' is identical to 'O'. 'A' is the same as 'R'. Yet
the human mind can often distinguish the correct letter by the
*context* in which it is used.

Upper case looks best. In the examples
below, most people have no difficulty reading 'DANGER' instead of
'OANGER', and 'UPPER CASE ONLY' instead of 'UPPEA CRSE ONLY'. In this case,
the 'R' and 'A' have the same shape, but are properly distinguished by
most people. The mind will boggle at things like 'DOODAR', because it has
no clues, and the identical letters are adjacent.
 _  _  _  _  _  _
| ||_|| ||_ |_ |_|
|_|| || ||_||_ | |

    _  _  _  _   _  _  _  _   _  _
| ||_||_||_ |_| |  |_||_ |_  | || ||  |_|
|_||  |  |_ | | |_ | | _||_  |_|| ||_  _|

There is more to this 'than meets the eye'. The brain is an
amazing thing!

Hope this helps.
Fr. Tom McGahee
----------
> From: Paul B. Webster VK2BZC <paulb@MIDCOAST.COM.AU>
> To: PICLIST@MITVMA.MIT.EDU
> Subject: Re: The Ultimate Peripheral: Another PIC
> Date: Saturday, July 25, 1998 7:23 PM
>
> Thomas McGahee wrote:
>
> > You can form reasonable facsimiles of the following: a b c d (e) f (g)
> > h i l n o r t u  A B C D E F (G) H I J L (N) O P S (T) U Y (Z) 0 1 2 3
> > 4 5 6 7 8 9. So you can send out messages such as <Hello Bill> by
> > scrolling the data to the left slowly.
>
>   I can accept that l = I = 1, Z = 2, S = 5, B = 8, g = 9, O = 0, but I
> can't really see how you can distinguish D from O or f from F.
>
> > You can do some simple "animations" by having the segments appear to
> > walk around in circles.
>
>   Yes, real neat!
>
>   Can you explain your two-wire protocol a bit more?
> --
>   Cheers,
>         Paul B.