Re: Cycles per ASM instruction

hancock4@[EMAIL PROTECTED]
 wrote:
> On Feb 21, 12:32 am, Arthur T. <art...@[EMAIL PROTECTED]
> wrote:
>>      I remember seeing them for the 370/115.  It's hard to forget
>> that moving from a 360/22 to a 370/115 gave us a CVD timing worse
>> by one to two orders of magnitude.  IIRC, the number of cycles for
>> that instruction was approx 250.
> 
> 
> Are you saying the 370-115 was slower than the 360-22?  (I didn't even
> know there was a model 22).
> 
> When I had exclusive use of a machine (actually the similar Univac
> 90/30), I experimented with using binary vs. packed-decimal.  Binary
> was faster internally, but the CVD and CVB instructions were killers.
> You had to be careful they were outside any loops.  (This involved
> COBOL subscripts).
> 
> 
> To this day proper definition of subscripts and SEARCH arguments in a
> COBOL program will save processing time if the files have any length
> to them.  We learned the im****tance of which field to use, but I'm not
> sure all programmers were taught it or remembered it from class.
> (Many were taught but probably forgot.)
> 
I used to work at a Fortune 100 manufacturing company where the COBOL
programmers regularly used display decimal subscripts because they
were easier to decode in a dump.

They also did stupid things like using prohibited COBOL contructs in
CICS programs, because they tried it and it worked. Of course CICS
needed to be cycled daily to recover memory lost to the OS.

	Jerry