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You need to find out about VGA mode 13 (I think), this willl then allow you to draw to screen, pixel by pixel....
Text-Editor, first you need to have a System Call Interface, and then develop some I/O functions for Disk access and get a file system. And then it is basically the same as your console, you have to create a buffer for the file. And then just add it so that with certain keys it copies this buffer to disk or vice-versa
Mode 13h is 320x200x256 color resolution. I have created a relatively basic GUI in this mode...
If you actually want a higher resolution, then I would recommend looking into VESA (http://www.vesa.org) or even video card drivers. VESA should allow between 640x400(and 640x480) - 1200x1024 in anywhere from 256 colors to 16.7million colors... beware, VESA takes a little more work than mode 13h. I recommend that you first develope the GUI in mode 13h (quick and easy)
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