Re: System 3 Code

[Douglas Handy <dhandy1@xxxxxxxxxxxxx>]

Lisa,

>A contractor recently described some very old code as "System 3" code.  Any 
>idea
>what this is?  RPG II is as far back as I go!  

There were numerous models of the S/3.  All but the largest (the model
15D) were basically batch machines using card (80 or 96 column) or
diskettes as the primary batch data medium.  I don't recall tape
drives on anything but the 15D (at least in my experience).

It did use RPG II, but it was more limited than the RPG II you may be
familiar with.  A primary file was *required* for the program to
compile.  No such thing as Full Procedural files.  No call/parm.  No
LDA.  No data structures.  No named EXCPTs.  No IF or DO, etc.  No
Workstn files.  Subroutines *had* to have SR coded in every line in
col 7-8.  Etc.

Lots of indicators and GOTOs.  Multi-format files with sequence
checking in the I-specs, particularly for transaction batch data.
Control breaks and even matching records were *very* common.  But then
Lx and MR are nearly ideal in this environment.  (Let's not start a
cycle war here.)  Frequent use of U1-U8, and even H1-H9 halt
indicators were useful.  (No flames please.)

The OS was called SCP -- System Control Program -- and was a precursor
to SSP on the S/34 and S/36 (the S/32 also used SCP).  The OCL was
very simplistic compared to what you see on the S/36 or even S/34.
You could have only one load statement per proc.  No substitution
expressions.  No LDA.  Made for some simple procedures. :)

The contractor may have simply been referring to the style of coding,
or it is certainly possible the programs originated on the S/3.  There
is  plenty of that code still in use -- or at least there was until
Y2K...

The S/3 model 15D supported actual interactive users on 3270 devices
using CICS (ala the mainframe folks), but when most people refer to a
S/3 they are thinking of a card or diskette based system using only
batch processes and run strictly by the operators.  The closest thing
to users were the data entry keypunch folks (3741, etc).

Doug
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