CICS itself is essentially just a way to put
up the forms for a user interface, but
a CICS application usually makes
heavy use of database, say, relational database,
e.g., DB/2 although there may still be some
IMS usage still hanging on.
One use of CICS was for heads down medical
claims processing, across all four US
time zones. The site our team from
IBM Research visited wanted high reliability:
If the site was down for, say, an hour,
then the data entry staff would have to
be called back on a Saturday, for at least
half a day, at a higher rate per hour.
One such outage in a year, and the CIO
could lose his bonus. Two and he could
lose his job. The site was very uptight.
Getting into the glass house was
not easy; might have been easier to get
into the White House Oval Office.
At one time to make CICS more secure,
there was some interest in having
processor hardware support for
address sub-spaces. Another
idea was cross memory where a
program could call and execute, say,
a function in another address space.
There were also data spaces, that
is, address spaces with just data and
no code but that could be accessed
by other address spaces with code.
Net, the IBM mainframes are not really
simple things. Cloning one would not
be easy, and at IBM's next version of
hard/software, the clone could be
unable to run the newer software and
suddenly be a boat anchor.
One use of CICS was for heads down medical claims processing, across all four US time zones. The site our team from IBM Research visited wanted high reliability: If the site was down for, say, an hour, then the data entry staff would have to be called back on a Saturday, for at least half a day, at a higher rate per hour. One such outage in a year, and the CIO could lose his bonus. Two and he could lose his job. The site was very uptight. Getting into the glass house was not easy; might have been easier to get into the White House Oval Office.
At one time to make CICS more secure, there was some interest in having processor hardware support for address sub-spaces. Another idea was cross memory where a program could call and execute, say, a function in another address space. There were also data spaces, that is, address spaces with just data and no code but that could be accessed by other address spaces with code.
Net, the IBM mainframes are not really simple things. Cloning one would not be easy, and at IBM's next version of hard/software, the clone could be unable to run the newer software and suddenly be a boat anchor.