Systems Programming

>Systems programming, on the other hand, seems to be a dying art.

yes, almost everywhere.  Your System/390 stories bring back memories - some
not so good.

"The risk is that a new IBM PTF or operating system release will change the
internals and your beautiful MI program will no longer work or worse, could
damage the machine."

I wrote code that was release-sensitive.  I crashed a system/38 with an MI
program.  I had the poor taste to write over the Work Control Block Header.
Check out the first few fields in there.  Until your story below, I had
never heard of anyone else who had crashed a System/38 or AS/400 with a
program.

"Over the past 7 years IBM has responded to this situation by creating many
supported APIs that permit an application to access various system
resources."

Longer than 7 years, more like 13 years.

The effort was caused by a small bunch of wackos writing MI programs on the
System/38.  Some of us didn't call system programs to do the work, we just
hacked the data areas.  Big sin but that was then - we are smarter now.
Some of that pretty good hacking went into program products that customers
liked a lot.  As they worked on the AS/400, it was clear to IBM, even if not
to us, that some of those hacks weren't going to survive the conversion from
S/38 to AS/400 - especially things like events.  There was an MI group at
Common and IBM started to show up and ask us hard questions.  We met in BOFs
during 1987 and 1988 I think.  I had written down who led the IBM side but
that is not my story to tell.  There were some very interesting silent IBM
people there - and some not so silent.  The outside programmer group had no
real leader (this was a bigger problem that any of us appreciated at the
time) but 15 to 30 people showed up for BOFs at three or four Commons.
After thinking about it, this is a long story so I'll stop now.  If you want
to hear it, let me know.  I think that I could get a group together who
would know most of the facts.  Steve, my memory isn't that good anymore for
things in 1987, where you there for those meetings?  Did I run into you at
Rochester for the System C testing?

"In summary, you might want to have some of us develop sample projects that
could be used for a semester course in MI...running in user state of
course."

That sounds like fun.  I haven't taught MI since the 80s at Common.  I
wonder if I still remember how ...  With ILE C, I'm not sure it makes sense
to write  MI any more.

I had to teach myself MI.  I wonder how easy we should make it to learn?
For that reason, the idea of an e-course doesn't appeal to me.

Richard Jackson
mailto:richardjackson@richardjackson.net
www.richardjacksonltd.com
Voice: 1 (303) 808-8058
Fax:   1 (303) 663-4325

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