Block Buffering

  One requires a finer grained access to storage than availabe. Therefore:
Read and write blocks of values at the required (desired) grain size. Hold one or more whole blocks in a buffer memory while the finer grained elements are processed.
  The CDC-6000 reads and writes 60-bit words. Four 12-bit PDP-8 words are buffered inside the FETCH and STORE macros.

The CDC-6000's paper tape punch driver expects Five 8-bit bytes in each 60-bit word of a binary file.

FORTRAN's formatted I/O reads and writes whole lines consiting typically of 80 to 132 characters.


PDP-8 Simulator
© 1975, 1998, Ward Cunningham
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