[cctalk] Re: Random items on Pascal #3

On Fri, May 10, 2024 at 8:45 AM Paul Koning via cctalk <cctalk(a)classiccmp.org> wrote: ESPOL was likely a major inspiration for SPL (System Programming Language) for the Classic stack-based HP 3000 which was used to write the MPE operating system (there was also no separate assembly language). The constructs in SPL map pretty much directly onto the hardware features, and it has an ASSEMBLE(...) statement for in-line machine code which is used frequently because an SPL programmer knows what's happening at the machine level and sometimes you just want to ASSEMBLE(SWAP, DUP) etc. SPL was a very machine-specific language designed explicitly for its machine. It was picked up by Tandem (perhaps literally off someone's desk when they weren't looking) to create TAL which was used to develop Tandem's original NonStop operating system for their machine which was, er, "inspired" by the original HP 3000 design. Later when HP migrated MPE to PA-RISC, there were eventually two different PA-RISC SPL compilers developed, one (SPLash!) by Allegro Consultants, and one internally by HP that was used to migrate the TurboIMAGE DBMS to native code (after their attempt to replace it with a new HP IMAGE based on a relational kernel crashed and burned),