(Multiline) Edit Control Limit
Reading one of msdn's technical articles and having experimented with the edit control I found this:
This raises the question of how are "large-scale text editors" created then, notepad can edit massive amounts of text over the limit of 64k? Using Spy++ the class of the input control on notepad is an "edit", I don't know if they have edited this or it is actually an edit control. There are alot of text editors out there and the edit control stuffs up the line numbering when the multiline edit control has >= 10 lines (I don't know if this is just my app). Also from the quote:
Edit controls were designed to enter, display, and edit small amounts of text. They were not meant to be the basis for large-scale text editors. Edit controls in Microsoft® Windows™ have the following limits:
Multiple-line edit controls are limited to a maximum of 64K (65,535 bytes) of text. Whether a multiple-line edit control is actually able to approach this limit is based on how the edit control uses memory. - http://msdn.microsoft.com/en-us/library/ms997530.aspx
Note the word "approach" this does not include going beyond like notepad (and probably other apps do). If anyone has heard of UEStudio (a commercial IDE), the main input control has a class called "EditControl" this can display rulers within it, the number of lines within the file and lots of other stuff including multi-colours.
Whether a multiple-line edit control is actually able to approach this limit is based on how the edit control uses memory.