18 Feb
2025
18 Feb
'25
7:45 p.m.
On Sun, Feb 16, 2025 at 11:12 PM ben via cctalk <cctalk(a)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).