|Here are the distinctions that I make|
Message #13 Posted by Dave Hicks on 25 Aug 2003, 12:30 p.m.,
in response to message #1 by Katie
Machine vs. Electronic
This is pretty simple. Although many people will refer to computers as machines, I think you know the distinction I'm making here. Some machines are electrically driven though the logic is mechanical.
Adder vs. Calculator
This is a little more fuzzy but there are devices that make division and multiplication "easy" and those that don't. Mechanical calculators usually have a carriage that can be shifted. For example to multiply a number by the number 1024, you would enter the first number, then turn the crank 4 times, shift the carriage, turn twice, shift the carriage twice (skipping the zero) and then turn the crank once more. Electrically driven machines can do all this at the push of a button. Even the basic adding machine sometimes provides at least a little support for multiplication however. For example, you enter your number and press the repeat button down and pull the lever 3 times. Push the repeat button back and pull the lever again (number * 4 is now entered). Now enter the number times 10 and you can figure out the rest...
These distinctions form a 2x2 grid with the boxes being
Mechanical Adder (or Adding machine.)
There are many examples of these for example...
These devices frequently (but don't always) print.
There are many examples of these too but the general public is almost completely unaware. These devices usually don't print. (I guess only a banker needs an "audit trail".)
While theoretically possible, I can't think of a good example. Because electronics are so cheap and calculator functions are now generally a matter of software, there seems to be little reason to leave multiply and divide out. Having said that, someone's probably got one for sale on ebay. Perhaps built into a ruler, keychain or a mouse ;-)
I'm sure you know what these are.
The above distinctions are different than the question of what logic system is used (though there's a lot of overlap in practice.) Most machines are essentially postfix with around two to three registers (not really a stack). One of the registers is frequently the keyboard or the key levers.
Electronic calculators come in Algebraic (a term covering many logic systems), RPN/L, and what I call "adding machine logic". The latter refers to electronic calculators for accountant-type functions. These calculators (usually with printers) do + and - in a postfix way (clear x + y +), * and / in an infx way (x * y =) and are usually now electronic though with a mechanical impact print head that produces more or less the same printout that adding machines have produced for centuries.
As for computers vs. calculators, I assert that almost all modern calculators are computers which are programmed to behave like calculators. This trend began when Busicom contracted Intel to build the chips for an early electronic calculator. Intel thought the design was too complex (27 different chips) and counter-proposed a 4 chip design (ROM chip, RAM chip, I/O chip and... the first microprocessor that would later be called the Intel 4004.)