gnu@sun.uucp (John Gilmore) (12/10/83)
It had a "real" accumulator and multiplier/quotient register, but the "index registers" were in core locations 1, 2, and 3 (this was in the days of real "core" core, too, with 3.6us cycle times). Its sister machine, the 1800 process-control computer, had the registers in real registers, so if you wanted your code to be portable you couldn't take advantage. Not that there was any advantage anyway...