Revision V2.10
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 created on Monday, 20.12.93 23:27:46  by  Frank Mariak.   LogMessage :
   - added BitMapCheck in MakeVPort ...  Sometimes the previous used
     BitMap was freed and i tried to use it again to store my
     videoram in fastram .... this caused some very bad deadlocks

 Revision V2.8
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 created on Sunday, 19.12.93 20:23:00  by  Frank Mariak.   LogMessage :
   - fixed bug in Driver-Initroutine. AASprites never worked with
     this bug
   - changed main datastructure
   - Lores/Hiressprites work now. Hotspot in LoresSprites is
     still wrong

 Revision V2.6
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 created on Friday, 17.12.93 17:05:40  by  Frank Mariak.   LogMessage :
   - fixed bug that GetDispInfoData always returned 0xffff for
     result buffer size if DTAG_MNTR was specified
   - fixed refresh display problem that occured since v2.5 because i
     removed some code

 Revision V2.4
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 created on Sunday, 12.12.93 20:27:51  by  Frank Mariak.   LogMessage :
   - added clipping to bob functions
   - some internal source changes only

 Revision V2.1
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 created on Saturday, 11.12.93 16:13:15  by  Frank Mariak.   LogMessage :
   - some speed improvements

 Revision V2.0
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 created on Tuesday, 07.12.93 00:47:42  by  Frank Mariak.   LogMessage :
   - version history set to 2.0 to avoid confusion
   - displaybeep bug fixed. the system crashed if displaybeep was done
   - sprite clipping added. if the sprite coords are going to get negative
     the sprite image is clipped relative to the zero position
   - sprites are hidden now if a vilintuisup screen is displayed