Edge character

[Math1723]

I was looking at the documentation in TI Basic, and I ran across a
note that the cursor was character code 30, and 31 was "the edge
character". What is this edge character? I notice that "PRINT CHR
$(31)" prints a blank here, but that doesn't explain to me why it is
different from say the space character.

[winston19842005]

On 12/4/09 10:40 PM, in article
519866ee-4a22-4e02...@9g2000yqa.googlegroups.com, "Math1723"
<anony...@aol.com> wrote:

The "edge character" is what resides in columns 1&2 and 31&32 whenever you
are editing a line or inputting text that takes more than a line.
Don't know why that is what is placed in those columns, perhaps it is used
for parsing your input. I never looked further than this.

[Guillaume Tello]

winston19842005 a �crit :

Maybe a facility for the "editor": as long as it encounters chr(32) the
line is not ended, and when it reaches chr(31), it's the end of line!
and editing goes on at the next chr(32).

Guillaume.

[winston19842005]

On 12/5/09 3:53 AM, in article 4b1a1f97$0$997$ba4a...@news.orange.fr,
"Guillaume Tello" <houte...@orange.fr> wrote:

A peek at TI Intern would tell us. I'm not that interested at the moment! ;)
But two things: I do remember a bug where if you edited a line things got
fowled up and I always thought it had something to do with the editor code,
which as you suggest (and it is very plausible) uses those edge characters.
But I'd like to ask what would happen if you could embed an edge character
into your program (via Merge, whatever) and then you edited that line?

Second thing: To see how it looks when editing, you can do a CALL
COLOR(0,2,6)::ACCEPT A$
and then hit function-4 (CLEAR) (all that in immediate mode) and it will
keep the colors you specify for character set 0 (chr(30), chr(31)) and then
start entering program lines.

You will see the edge characters appear after the editor scrolls for the
next line, on either side of the screen, light blue. Your cursor will be
black with a blue background.