🚀 go-pugleaf

On Wednesday, August 15, 2018 at 5:42:29 PM UTC-4, Peter Flass wrote:
> Dan Espen <dan1...@gmail.com> wrote:
> > hanc...@bbs.cpcn.com writes:
> > 
> >> On Wednesday, August 15, 2018 at 7:09:42 AM UTC-4, Peter Flass wrote:
> >> 
> >>>>> All the rest other than OS were mistakes. IBM was unable to get
> >>>>> even PCP to fit on the smallest machines, so DOS, TOS, BOS were written as
> >>>>> "temporary" systems which became permanent.
> >>>> 
> >>>> Yes.  I never entirely understood the difference between BOS and DOS.
> >>>> I realize that BOS could run in 8K and DOS needed 16K, but what else
> >>>> did BOS leave out?
> >>>> 
> >>> 
> >>> I don't know that much about BOS either. I used to think it was a subset of
> >>> OS, but Bitsavers has some manuals and it appears it was a subset of DOS.
> >>> I'll have to read the manuals. I would assume it at least left out
> >>> multiprogramming. I think BOS could be run from cards.
> >> 
> >> I think the IBM S/360 history says BOS was intended as an 
> >> emergency operating system rushed out so the users would have
> >> something to use quickly.  It could also be used in very small
> >> systems--I believe S/360 was originally offered in only 8k (later
> >> raised to 16k).  DOS was also an emergency development, but
> >> DOS managed to be permanent.
> > 
> > An 8K S/360 would have been useless, OTOH,
> > lots of 8K 1401s worked very well.
> > 
> > IBM managed to design something so complex
> > that it needed an OS, and IBM couldn't shoehorn
> > the OS into 8K, let alone any applications.
> > 
> > An existing 8K 1401 shop would need a S330/30
> > with 64K.  Lots of places tried 32K, that never
> > worked well.
> > 
> 
> Most of my early career was developing software for customers with 32K
> 360/30s, and that seemed to work out quite well. Obviously basic batch
> applications: personnel, payroll, accounts receivable/payable, inventory,
> etc.

We had 128k.  I think most of our COBOL programs needed _roughly_
about 64k, though a few complex 3,000 line programs could use as 
much as 100k (on a 128k machine).  

I know some sites used COBOL segmentation to save space.  

Many sites in the early days used only assembler since that used
less space than COBOL, especially with a skilled programmer who
knew the memory saving tricks.