Re: The joy of FORTRAN-like languages

The Natural Philosopher <tnp@invalid.invalid> writes:

On 29/09/2024 05:26, Charlie Gibbs wrote:

That's assuming your machine has a stack, which the IBM 360 didn't.

Well there are probably other ways to implement a stack than having it
built into a computer.
Like a having a general purpose register reserved for a stack pointer
and manually creating push pop call and return as macros

Or actual machine instruction codes, as on the PDP-6 and PDP-10:

PUSH ac,address ;any accumulator can be a stack pointer
POP ac,address

PUSHJ ac,address ;address of next instruction on stack, jump to address
POPJ ac, ;pop address from stack and jump to it

There are also subroutine call instructions which do not use a stack, instead
using either the "save return address in first instruction of subroutine" or
"save the return address in an accumulator".  The former is nonreentrant; the
latter allows placing parameters inline, with address manipulation via indexing
to access and later skip over them.

Lovely machines to program.

--
Rich Alderson   news@alderson.users.panix.com
      Audendum est, et veritas investiganda; quam etiamsi non assequamur,
  omnino tamen proprius, quam nunc sumus, ad eam perveniemus.
--Galen