Crunching
numbers was a part of the task.  The other part was moving
 and handeling data in mass storage and memory.  Most of the DEC hardware
 moved data pretty fast. What was the demise of PDP-10 was simple, megabytes. 
 And being six bit machine in an eight bit world...
  
 SEVEN bit world. We can blame IBM for all our 8 bit PC ASCII stuff.
Eight bits I think for EBDC was earlier. Having 4 bit sized TTL stuff
does not make for nice octal digits. Ben.