Post by thread:[OT] Different Computer systems

Trivia ... !!! :-) ... From: John Payson <spam_OUTsupercatTakeThisOuTCIRCAD.COM> >|I guess that those based on Digital Binary are the most popular. >|But I know that there are/were others, like the Analog ones, and Ternary >|(3 states)? > >|Does anyone out there have some trivia on this? > This should be enough trivia to go on with - Ternary is the most efficient storage method available (at least using integer numbers). The most efficient is the natural logarithm base "e" (2.718...) but its a bit (pun unintended) hard to make 2.7-state devices so 3 is the best available. eg - consider d240 (= 2 x 3 x 4 x 10) This requires Base 2 = 16 states (2 states per bit x 8 bits) Base 3 = 15 states Base 4 = 16 states Base 5 = 20 states ... Base 10 = 30 (3 x 10 states ) Numbers equal to (base^n)-1 will give best results for that base. eg 999 2 20 states 3 21 states 4 20 10 30 Here binary just improves on ternary but even the optimised decimal (999 = 10^3-1) uses 50% more storage. Overall, Ternary wins. Nowadays Andy & Bill don't care about such things. I understand that the Russians made ternary based computers in the early days when the cost of storage and registers was extreme. Nowadays this is not a consideration and the great ease of using binary logic states ensures that binary rules. IBM made some early "mini-computers" which thought in BCD. Our university had one (circa 1969 !!!) and it could run Fortran 4 - but it took 2 passes as it didn't have enough memory to fit all the program in at once.. regards Russell McMahon (1210 years old)(base = ???)