HiRes Mover

Hi-res mover





Jan Erik Lundberg,


Solna,


Sweden.





Impressed by the smooth action of the hi-res graphics in


Psion's Planetoids for the Spectrum I just had to have a go


at writing a machine-code subroutine that could do a simi-


lar job. I hope that it will be useful for the readers who


want to write their own programs using moving graphics.


Overcomplicated Basic programs would be too slow but per-


haps a compiled version would be better.


The demonstration driver program is only intended to show


how to use the routine and demonstrate its good and bad


features.


See what happens when you change the mode - 0 to 3. The


subroutine writes or erases the user-defined graphic in


high-res - 172x256. You can expand them from 21 to 32. It


is position-independent coded, PIC, and you should start to


load it 600 bytes lower than the UDG pointer.