accumulator

1. Archaic term for a register. On-line use of it as a synonym for register is a fairly reliable indication that the user has been around for quite a while and/or that the architecture under discussion is quite old. The term in full is almost never used of microprocessor registers, for example, though symbolic names for arithmetic registers beginning in `A' derive from historical use of the term accumulator (and not, actually, from `arithmetic'). Confusingly, though, an `A' register name prefix may also stand for address, as for example on the Motorola 680x0 family.
2. A register being used for arithmetic or logic (as opposed to addressing or a loop index), especially one being used to accumulate a sum or count of many items. This use is in context of a particular routine or stretch of code. "The FOOBAZ routine uses A3 as an accumulator."
3. One's in-basket (esp. among old-timers who might use sense 1). "You want this reviewed? Sure, just put it in the accumulator." (See {stack}.)

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