sedwards@tybalt.caltech.edu (Stephen A. Edwards) (07/30/89)
I am working on a VLSI/SSI 32 bit stack machine, and it is at the point where the instruction set is being designed. Rather than omit instructions which some programmer someday will curse me for omitting, I figured I would ask now. A little about the architecture: It contains two almost identical stacks with reasonably powerful ALUs at the top: They can perfom logical operations along with add and subtract, and shifting. Main memory has a variety of registers to control addressing. The whole machine is very pipelined: most instructions require one cycle (and exception being memory accesses, which require two, and returns, which require none, similar to the Novix chip) My question for all you FORTHophiles out there is this: What instruction (or instructions) have you found absent in the language which would be very useful, or what additional instructions are in your favorite implementation which you would not do without? Thanks in advance, Stephen A. Edwards | sedwards@tybalt.caltech.edu