That shipping deadline and the insane fallout from it has done more to keep me employed in my career than anything else.
The BCD part is "binary coded decimal" - a way of representing numbers as decimal coded digits, so 0001 1000 meant "18".
The BCD Interchange code was a 6 but character set that allowed the standard encoding of uppercase letters and numbers. It was realised onto punched cards by utilising "digits" 11 and 12.
The extended binary decimal interchange code was a larger space (8-bit) that allowed the encoding of both uppercase and lower case letters.
Incidentally, the terms "upper case" and "lower case" come from printing presses where the individual letter punches (think the head of a typewriter) were stored in "cases" - actually a wooden storage drawer with lots of small rectangular components containing many of each letter; more for E and other vowels, less for Z and X - and since typesetting text involves more lower case than upper case (as per this post) the lower case letters were stored in the lower case so that they would be easier to reach, with the capitals being stored above and sightly further away.
You can play with OS/360 versions like MFT and MVT, read source code (or try!), do a system generation (recompile the "kernel") and run ita facilities.
Hercules-390 has a very active community .
PS: OS/360 and many other older IBM systems are now public domain and have almost all source code available.
These were first computers I was exposed to. As students and later young engineers working with them, we were taught an important principle: "nothing you can do in software can break the hardware". Imagine then my bewilderment when, working with a tape and having some strange-looking "Attention required", I went down to the ceiling only to see the tape still on reels but cut in two pieces.
Sounds like a cool uncle
I think what "modular" is alluding to in the title is that the 360 introduced a whole line of compatible computers, rather than making each computer a separate architecture as had been previous practice.
In other words, the 1959 IBM 1401 was modular in the sense of being made from modules, but it wasn't modular in the sense of being part of a product line. (The improved 1410 was only sort of compatible.)
SMS link: https://en.wikipedia.org/wiki/IBM_Standard_Modular_System
Not just component-wise upgradability or ease of assembly, but rather eliminating entirely the concept of doing one-off "integrations" to create new products in the line. In other words, doing with their computer parts what IKEA does with furniture parts: designing and manufacturing only at the component level, then feeding all the finished components into a shared pool of resources, where products are then simple assemblies of resources from the pool.
EDIT: $500mil-$1bil on development part per another comment.
> Estimates of the total cost of System/360 range from $4 to $5 billion. Of this amount, $500 million to $1 billion was development cost, while the rest was used to expand manufacturing capacity and to produce rental machines.
The references are Wise (1966b), Evans (1983 p.44), and IBM Annual Reports for 1965 and 1966.
Wise (1966b) is a Fortune article titled "IBM's $5,000,000,000 gamble".
I can't find the annual reports readily online.
It looks like you want Appendix C of "IBM's 360 and Early 370 Systems" at https://books.google.com/books?id=MFGj_PT_clIC&pg=PA619&dq=I... , with financial an employee data for IBM from 1950 to 1977.
In the early 1960s IBM had revenue of over $1.5 billion/year. Even then, 360 was a big gamble.
I think you're missing some 0's there.
In your essay, you wrote "development cost". Is that meant to include production? Because it appears the development cost as its own line item was no more than $1B.
Have you read Wise's Fortune article to confirm that it says what you think it does? I haven't been able to find it online.
Also, I think it's interesting that nearly all of the sources I found cite that Fortune article, and not an IBM publication. Even an IBM site prefers to quote Fortune instead of their own sources.
I agree. Not that any of this really matters but I hate when inaccurate figures are just repeated and taken as fact which is why I raised the point in my original question. Actually just because the number seemed to high to be true.
We've had two other cases of this that I can remember recently. One was the ADA and flossing. 
The other was the "8 glasses a day of water" which is something that has been repeated as gospel. 
As a general rule people will always throw in the kitchen sink when stating numbers and make them seem as large as possible.  Additionally anyone who was ever interviewed for a news story will know that whatever you repeat to a reporter is rarely questioned. It's taken as a fact and if it ends up in a major newspaper (say NYT or WSJ) it is taken as vetted and authentic. (I have been quoted so that is why I say this..)
 And now I am seeing this: http://www.ada.org/en/press-room/news-releases/2016-archive/...
 Unless of course it serves them to make them as small as possible.
Burroughs changed their name to Unisys. They still sell those machines although not with the custom CPU's with hardware-enforced safety/security. (sighs)