Interesting article in Spectrum about IBM's System/360

Jon Elson elson at
Fri Apr 12 22:20:13 CDT 2019

On 04/12/2019 12:41 PM, Carlos E Murillo-Sanchez via cctalk 
> Building the System/360 Mainframe Nearly Destroyed IBM
Yup, they bet the company on a new product.  it was a VERY 
well thought-out bet, but still a big reach.  One area they 
really made a mistake on was software.  They designed a 
really ambitious OS (OS/360 MFT) and then an even more 
ambitious version (OS/360 MVT) on a poorly thought-out 
timeline.  Fred Brooks actually had a nervous breakdown over 
it, and maybe some other guys, too.  Fred Brooks' "The 
mythical man month" is just too short, and doesn't have 
enough actual anecdotes, but is a good read anyway.  At the 
time he wrote it, there were probably a bunch of stories 
that he couldn't yet tell.

Also, the hardware was a huge leap.  IBM went from building 
computers with all purchased components on single-sided 
paper-phenolic PC boards to making their own transistors and 
diodes and packaging them on little ceramic hybrid modules, 
and then putting those on 4-layer PC boards.  They pioneered 
a LOT of packaging technology on the 360.  The developed 
flip-chip bump-bonding of semiconductors, and were doing 
this almost 20 years before anybody else were doing this.  
But, of course, there would be growing pains with such 
development.  The entire state of New York was a bustling 
beehive of computer manufacturing.  They made disk and tape 
drives, printers, hand-assembled close to 20,000 mainframe 
CPUs plus all the controllers and memory, between 1965 and 
1969. Totally mind boggling!


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