There are many people here who used the UofM mainframe back when it was updated on a chargeback system (including me, sadly, although my Dept paid the bill, not me).
Of course I didn't keep a copy of the rate sheet, so I don't remember what 1sec cost.
It wouldn't quite be the fully-loaded cost you describe, but it would be close - I don't think Computer Services was expected to turn a profit back in 1991.
-Adam

On October 25, 2021 8:56:07 p.m. CDT, Brian Lowe <brian2@groupbcl.ca> wrote:
Hello all,

Today with multi-core CPUs running at gigahertz speeds attached to gigabytes 
of RAM and terabytes of disc space, we're well used to running programs that 
require what would be enormous resources back when mainframes ruled the data 
centre.

My question is "how much did one second of computer time cost in 1975?" This 
assumes the program in question is being run on a mainframe from IBM or any of 
the other manufacturers of the day. Of course, there are a lot of factors to 
consider: leasing costs, staffing, power and cooling, if the system could run 
more than one program simultaneously, and how computer time was charged back 
to the users.

I'm interested to know if anyone on this list has had experience with this 
sort of system accounting, and if they can recall some numbers.

Regards,
Brian
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