README file for vt52 vnc viewer, (c) 1999 Milan Pikula

0. About

1. License

2. Installation & running

3. Bugs & features

4. Contact

5. About

   vt52vnc is a VNC ( http://www.uk.research.att.com/vnc ) viewer, which can be used on old, green, monochromatic, prehistoric terminals labeled vdt52s, which are capable of vector graphics. The software is functional, but incomplete: it does not support compression, passwords and there are many ways to optimize the output.

6. License

   This software is distributed under the terms of GNU GPL license, see `COPYING' file.

7. Installation & running

   1. edit Makefile to adjust some parameters, vi Makefile
   2. run `make' make
   3. optionally install: cp vt52vnc /usr/local/bin

8. Bugs & features

   Mouse:

   As vdt52s does not have the mouse or any other pointing device, one of three unlabeled buttons near the numeric keypad have been used to act as mouse-lock. When you depress it, you can use the numeric keypad to move the mouse, and +', -', .', enter', 0', and 5' as button 1,2,3 toggle and button 1,2,3 click.

   Speed:

   Based on my own experiences, I recommend the speeds 38400 and higher for "real work". The screen is drawn by rectangles. This is done to improve the reaction times, when the screen changes very often.

   The software uses the XOR mode to actually draw the image, which can be improved using AND and OR mode in some cases. One can also imagine another optimizations for particular shapes. I will not add those optimizations, as the decisions are very memory-consumptive and after all, I don't want to implement some kind of prolog just to choose the right one. If you want to improve it, let me know.

   Colors:

   The monochromatic translation is done by some bit of green color, which can be changed at the beginning of vncproto.c. If you want to make it better (implement some dithering or (better) the shape finding algorithm), let me know.

   Why and how:

   The work was inspired by mine never-ending desire for an X display on the "frog". Display drawings are based on the graphics library by Marek Zelem, which is, in turn, based on the documentation for vdt52s, as my work is based on vnc protocol documentation. Coded, of course, on vdt52s terminal with wrong Enter and Control. The sources are written to be easily extended.

9. Contact

   Milan Pikula, www@terminus.sk or www@fornax.sk