Re: Cycles per ASM instruction

"Jerry Peters" <jerry@[EMAIL PROTECTED]
> wrote in message 
news:fXnDh.4218$as2.2121@[EMAIL PROTECTED]
> 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.

Have you ever come across this COBOL programmer who for his application
needed a parameter that would change say one a year or so and naturally
prepared a dataset with one record to hold the parameter? Very sensible I
would say until we discovered that this programmer was familiar with only
one dataset organisation: The ISAM dataset.

He had actually prepared a fully indexed dataset with just one datarecord
which his program read sequentially each time it was run!

regards Sven