The Importance of Terminology's Quality

Arne Vajhøj arne at vajhoej.dk
Wed Aug 13 02:40:07 CEST 2008


Robert Maas, http://tinyurl.com/uh3t wrote:
> John W Kennedy <jwke... at attglobal.net> wrote:
> JWK> Into the 60s, indeed, there were still machines being made
> JWK> that had no instruction comparable to the mainframe BASx/BALx
> JWK> family, or to Intel's CALL. You had to do a subprogram call by
> JWK> first overwriting the last instruction of what you were
> JWK> calling with a branch instruction that would return back to
> JWK> you.
> 
> That's not true, that you needed to do that, that there was no
> other way available. The subroutine linkage I invented for S.P.S.
> (Symbolic Programming System, i.e. IBM 1620 assembly language) was
> to reserve a 5-digit space immediately before the subroutine entry
> point for storing the return address. So the caller needed to know
> only one address, the entry point, and do both store-return-address
> and jump relative to that address, rather than needing to know both
> the entry point and the last-instruction-JUMP-needs-patch address
> as independent items of information.

CDC Cyber did something very similar.

Not very recursion friendly.

Arne



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