Hmm -

Tom Watson sdc695 at
Fri Mar 23 12:54:07 CDT 2007

On Thu, 22 Mar 2007 19:20:51 -0700, "Chuck Guzis" <cclist at> wrote:

> On 22 Mar 2007 at 14:59, Steve Wilson wrote:
> > >4900796  (Somebody will understand this reference)
> > 
> > Someone is trying to boot Fortran off of the Disk on an IBM 1620 me
> Isn't 00796 where all-well-behaved programs went to die? I.e. reload 
> Monitor (sort of a CALL EXIT)?
> --Chuck

We have a winner.  
Just to add to the trivia, to boot the disk you needed a few more characters:
Which if you were on a model 2, you needed to make sure that indirect
addressing was turned on (nothing worked right if you didn't!).

After doing that a few times, you remembered it pretty well.

OB Fortran reference:
There were several "load & go" Fortrans available for the 1620.  The one I
liked the best was Witran.  It fit into a 20k machine, but was interpreted. 
Still not too bad for a Fortran.  The best was the Monitor II Fortran II.  It
generated automatic floating point instructions, and used index registers (only
for the compiler I think).  Pretty speedy.  The hardware floating point on a
1620-II was faster than the software on the (next generation) IBM 1130 (I used
that too).  The 1620's bonus was that standard precision (in floating point)
was 8 significant digits.  If you really felt ambitious, you could go MUCH
higher (28 digits with Fortran-II).  Few machines today can match that in hardware!

Tom Watson
tsw at

Get your own web address.  
Have a HUGE year through Yahoo! Small Business.

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