Question: Suppress or show output in Maple

Hi. I'm new to Maple. I like the idea, but am rally confused by the interface. Can someone answer a few questions please?

How come this works, but displays wrong (the quotes display):

printf("%5a  %12a  %12a   %12a  %12a  %12a  %12a\\n", "-", "--", "--", "--", "--", "--", "--");

 

But this doesn't work (replaced quotes with apostrophe):

printf("%5a  %12a  %12a   %12a  %12a  %12a  %12a\\n", '-', "--", "--", "--", "--", "--", "--");

 

Yet this works (used apostrophes for all):

printf("%5a  %12a  %12a   %12a  %12a  %12a  %12a\n", 'i', 't[i]', 'k[1][i]', 'k[2][i]', 'k[3][i]', 'k[4][i]', 'w[i]')

I am told that putting a colon(:) after a line in Maple will suppress the line's output. However, this does not always seem to be the case. I cannot find any documentation which tells me when it is, and when it isn't, or how to do displays properly. The biggest problems seem to occur in loops:

for i to N do

t[i-1] := a+(i-1)*h:

k[1] := h*f(t[i-1], w[i-1]):

k[2] := h*f(t[i-1]+(1/2)*h, w[i-1]+(1/2)*k[1]):

k[3] := h*f(t[i-1]+(1/2)*h, w[i-1]+(1/2)*k[2]):

k[4] := h*f(t[i-1]+h, w[i-1]+k[3]):

w[i] := w[i-1]+(k[1]+2*k[2]+2*k[3]+k[4])*(1/6):

end do;

See all those lines with colons after them? The output on all of them displays. They shouldn't!

Why does Maple add quotes when I try to paste into an already-quoted literal in a printf line. Supposed I wanted to add a %12a to the following line:

printf("%5a  %12a  %12a   %12a  %12a  %12a\n\n", 'i', 't[i]', 'k[1][i]', 'k[2][i]', 'k[3][i]', 'k[4][i]', 'w[i]');

If I select one of the '%12a', Ctrl-v, then Ctrl-c, it adds quotes. What's up with that?

And why does Maple sometimes paste lines in a different spot than my cursor? Usually, it's at the end of the line above my cursor, but sometimes it's in the middle of the line below.

Also, can I extend the Undo buffer size? Any other UI information will be appreciated (I guarrantee that, since I am banging my head up against this UI). NOte that I am using Worksheet Mode.

Signed,

Confused and intrigued by Maple