> From: Dave McKenzie > > The modified machine instruction in UNDELM is in the VMCRD subroutine > (showing its CISC heritage: VMC was the "vertical microcode" on > CISC--what is called SLIC, System Licensed Internal Code, on RISC). This is interesting stuff for me, Dave. I remember the terms vertical and horizontal microcode, and I never quite understood which was on top of which, and why. I understood that they provided the software/hardware isolation that has done us such service over the years, but not the exact mechanism. And now with the SLIC, I am less sure as to how that works. Would you care to share a little more of your wisdom with a layperson? <grin> Joe
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