home *** CD-ROM | disk | FTP | other *** search
/ NetNews Usenet Archive 1992 #26 / NN_1992_26.iso / spool / comp / arch / 10622 < prev    next >
Encoding:
Text File  |  1992-11-11  |  1.4 KB  |  43 lines
  1. Organization: Robotics Institute, Carnegie Mellon, Pittsburgh, PA
  2. Path: sparky!uunet!ferkel.ucsb.edu!taco!gatech!swrinde!zaphod.mps.ohio-state.edu!cis.ohio-state.edu!news.sei.cmu.edu!fs7.ece.cmu.edu!crabapple.srv.cs.cmu.edu!andrew.cmu.edu!jb7m+
  3. Newsgroups: comp.arch
  4. Message-ID: <4f0IQEm00WD5IXXKNc@andrew.cmu.edu>
  5. Date: Wed, 11 Nov 1992 12:46:56 -0500 
  6. From: "Jon C. R. Bennett" <jb7m+@andrew.cmu.edu>
  7. Subject: Re: MINIMUM instruction set
  8. In-Reply-To: <1992Nov11.144304.10494@news.uiowa.edu>
  9. References: <1992Nov10.235849.19192@fcom.cc.utah.edu>
  10.     <1992Nov11.144304.10494@news.uiowa.edu>
  11. Lines: 30
  12.  
  13. jones@pyrite.cs.uiowa.edu (Douglas W.Jones,201H MLH,3193350740,31933828 writes:
  14. > From article <1992Nov10.235849.19192@fcom.cc.utah.edu>, by val@news.ccutah.edu\
  15. >  (Val Kartchner):
  16. > > I've heard that it is possible to implement all programming languages with
  17. > > seven instructions.
  18. > 
  19. > What is an instruction?  Ignoring I/O, the following CISC instruction does
  20. > the job:
  21. > 
  22. >         DB <op1> <op2> <op3>
  23. >                 Decrement <op1> by <op2> and branch to <op3> if the result
  24. >                 is less than zero.  All operand fields address memory.
  25.  
  26. i think that perhaps a better question, and one which i think you almost
  27. answered is, "How many operations are needed...."
  28. the instructions that you present do the following
  29.  
  30. load
  31. store
  32. subtract
  33. compare
  34. branch
  35.  
  36. the only things i can think of that are missing are
  37.  
  38. shift
  39. bit op (and,or,xor)
  40.  
  41.  
  42. jon
  43.