Re: System 3 Code

I'll agree with you there Mel...  Some folks just don't know how good they have 
it now.

Mel Rothman wrote:

> Most System/3 computers had disk drives.  Only the very early System/3 Model 
>10s
> lacked disk I/O.
>
> The first two models were System/3 Model 10 (first a card-only version with a 
>MFCU
> (multi-function card unit); later one with disk I/O and MFCU)) and System/3 
>Model 6
> (no punched cards, keyboard/printer console, disk).  System/3 was announced 
>in 1969.
>
> Later models were quite powerful for their day.  My last project as an IBM 
>Systems
> Engineer was designing and programming an online (3270 CRT terminals) system 
>for a
> credit union on a System/3 Model 15D.  The system went live on January 3, 
>1978.
>
> That particular System/3 had 384K bytes of memory, 3 partitions, and
> about 140 MB of disk storage (two removable 3340 disk drives - the platters, 
>heads,
> and arms were sealed inside the removable cartridge).  By October 1976, the 
>credit union
> was running 25 3270 terminals on the System/3.  By that time, most System/3s 
>were cardless
> with unit record I/O handled by direct-attached 3741 diskette data stations.
>
> The programming language was RPG II, which supported sequential, and direct
> (by RRN or KEY), disk I/O.  Exception output was also supported.  There were
> no externally described files, no IF, DO, SELECT, FOR, CASxx, etc., op codes.
> There was no database (flat files only), no journaling, and no commitment 
>control.
>
> RPG II was the only language at first; it was later joined by COBOL and 
>FORTRAN.
>
> Relational databases hadn't been invented.  Spooling was supported only for
> system printers (I don't remember whether more than one per system was 
>supported)
> and the system spool file could fill up!  Maximum program size was 64K.
>
> The Communications Control Program (CCP) supported online programming.
> CCP programs could not exceed 32K.  The RPG II compiler supported external 
>buffers
> and external memory resident overlays.  Screen I/O was supported by DFF
> (Display File Facility), which I think was part of CCP.  There was no SEU,
> but a field developed program for online editing of source members was
> widely used.  The disk was organized in two major parts: a library section 
>(contained
> procedures (OCL - operation control language), source, object (executable 
>programs)
> and relocatable object (generally system-provided to be be link edited into 
>programs);
> and, a file section for user data, including a VTOC (volume table of 
>contents).
>
> System/3 was the ancestor of System/32, System/34, System/38, System/36,
> and AS/400, in that order.  System/32, System/34 and System/36 all were
> System/3 derivatives.  System/38 and AS/400, of course, were and are
> completely different and far more advanced than the others.
>
> That's the way it was (as best I can remember) and is (as I best can
> understand).  Any errors are certainly my own!
>
> I would have to agree that "System/3 code" is very old indeed!  It certainly
> wasn't as bad as walking 5 miles to and from school in the snow, uphill both 
>ways,
> or programming on card-only machines, but compared to today's programming
> environment, it was pretty primitive.
>
> Programmers whose experience only goes back as far as AS/400 (announced 1988)
> or even System/38 (announced 1978, shipped 1980), often don't know how good
> things are.
>
> Mel Rothman
>
> booth@MartinVT.com wrote:
> >
> > System 3 machines were mostly card machines.  They used 96  column punched
> > cards to store data.  RPG responded to those needs, not to magnetic media.
> >  You designed with record formats, matching records, level breaks, and
> > left-side indicators.  there were no parms, no calls, no *INZSR, no
> > externally described files, and no logical files.  you sorted the records
> > to establish order for reports.   Source code was numbered in the first 5
> > columns so you could put your card stack back in order when you dropped
> > it.
> >
> >
> > _______________________
> > Booth Martin
> > Booth@MartinVT.com
> > http://www.MartinVT.com
> > _______________________
> >
> > Lisa.Abney@universalflavors.com
> > Sent by: owner-rpg400-l@midrange.com
> > 09/26/2000 08:42 PM
> > Please respond to RPG400-L
> >
> >
> >         To:     RPG400-L@midrange.com
> >         cc:
> >         Subject:        System 3 Code
> >
> > Just a curiousity question ...
> >
> > 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!  I do know it's running on
> > an
> > AS400 in 36 mode.
> >
> > +---
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