bit bashing

bit bashing n.  (alt. `bit diddling' or {bit
   twiddling}) Term used to describe any of several kinds of low-level
   programming characterized by manipulation of {bit}, {flag},
   {nybble}, and other smaller-than-character-sized pieces of data;
   these include low-level device control, encryption algorithms,
   checksum and error-correcting codes, hash functions, some flavors
   of graphics programming (see {bitblt}), and assembler/compiler
   code generation.  May connote either tedium or a real technical
   challenge (more usually the former).  "The command decoding for
   the new tape driver looks pretty solid but the bit-bashing for the
   control registers still has bugs."  See also {bit bang},
   {mode bit}.