>> DEC PDP-10; the registers were also addressable as the first 16 >> memory locations. You could even put code in the registers and >> jump to them, for a speed boost. > IBM 1130: The 3 INDEX registers (but not the accumulator) were in memory and could be addressed that way, including Indexing the Index registers.... :-) -- Bob Ammerman -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist