An option is to use the BITBLT instruction which could be called from BCPL: ftp://bitsavers.informatik.uni-stuttgart.de/pdf/xerox/alto/BitBLT_Nov1975.pdf Dan

An option is to use the BITBLT instruction which could be called from BCPL: ftp://bitsavers.informatik.uni-stuttgart.de/pdf/xerox/alto/BitBLT_Nov1975.pdf Dan Ingalls showed how to implement the Game of Life and how to rotate bitmaps using this instruction in a SIMD style. While BITBLT implemented all 16 possible boolean functions, not all were equally fast.