Variable Word length CPU

[William Donzelli]

> I think the reality here is somewhere between "yes they did" and "no they
> didn't".

Pages 465 thru 479 of "IBMs Early Computers" holds the story. Required
reading.

The roots of the 1401 project, called SPACE, goes back to the RAMAC days,
apparently.
 
>  A single 1401 could be much faster and do more
> complex operations than the unit record equipment, but the old stuff was
> very robust and economical.

Remember, however, that the unit record equipment was starting to show it
age. Being electromechanical in nature, failures went up over time, just
like an old car. Fixing the things was mostly on IBMs dime.

> IBM was actively trying to upgrade their customer base from UR to computer
> for a long time.  I recall that a friend in the late 60's was excited that
> his employer, a small Chicago area manufacturer, had just upgraded from UR
> equipment to a 360/20 on the advice of an IBM SE.  Lots of interesting new
> stuff and new tricks to perform.    He thought it was wonderful.

The "fake" S/360 was the second attempt to kill off the old stuff. S/3 was
the third and final stab, and it pretty much worked (although 083s were in
use until the very end).
 
> The point of this is that even during the 60's, IBM was still actively
> recommending and leasing UR equipment.

I would think that was the exception rather than the rule. Certainly they
would have wanted to lease or sell more 1401s than the older systems.

William Donzelli
aw288 at osfn.org