On Sun, Feb 16, 2025 at 11:12 PM ben via cctalk <cctalk@classiccmp.org> wrote: > > Did any classic computers have a subroutine call as (S++)=PC, PC=(EFA) > as well as the standard call (--S)=PC,PC=(EFA) ?
The Classic stack-based HP 3000 has both PCAL (Procedure Call) which lays down a complete stack marker and creates a new local stack frame, and SCAL (Subroutine Call) which just takes an address (technically a Local PLABEL) off the stack and leaves the return address. There are corresponding EXIT and SXIT instructions. There's also a PARC (Paragraph Call) and ENDP for use by COBOL (because COBOL allows nutty things).
