Re: Mainframe Interactive Programming

[Dan <dan27649@xxxxxxxxx>]

I don't recall the maximum size on the S/34, but it was definitely 64k on
the S/36.  I know this because I toiled many, MANY times trying to get a
program to compile.  I think it took about an hour for the compiler on the
system I remember using before it aborted due to exceeding the 64k limit.
I remember that you could save one byte by changing
SETON    091008
   to
SETON    080910
because the compiler could optimize this operation when the first indicator
was a factor of 8 and the next two indicators were +1 and +2 of the first
indicator.

I'm certain we used programming techniques that would horrify us today,
just so we could get that program within 64k.  Speaking of which, does
anyone remember the DataNetwork monthly contests that looked for the
smallest number of lines of code to perform a certain task?  There were
some amazing techniques, some of which were used in efforts to get within
the 64k limit, but they were awful in terms of readable code.

RPG-II definitely had subroutines.  I'm pretty sure RPG 1.5, which I
learned in college on an IBM 1130, had subroutines as well.

- Dan

On Fri, Jun 8, 2018 at 1:15 PM, Jonathan Wilson <piercing_male@xxxxxxxxxxx>
wrote:

> Not quite as old... but I vaguely remember doing that on the S36. But,
> I'll be honest, apart from remembering the term - NEP-MRT - I remember
> exactly ziltch of how it was done. I also recall having to break up a
> larger program on occasion and, if I recall correctly, using the display
> file - or possibly the LDA - to pass key(ish) information between so it
> looked like one single program when the original one blew past the
> maximum size. I honestly can't remember what the maximum size was, but
> it was a right PITA when it happened because invariably the huge
> monolithic original program wasn't designed to be cut up and every
> single line had at least one indicator denoting which display record was
> currently being processed. Did the language even have subroutines, it
> was such a long time ago, or was I just unlucky that the original
> programmer hadn't thought to use them?