Re: Re: Anyone need a random number generator?

On 4/30/2010 12:34 AM, Ron Hudson wrote:
>     //      UNIT=SYSDA,SPACE=(TRK,(1,1,1)),DCB=(RECFM=U,BLKSIZE=1024)
>
> oh, wouldn't that also mean that the resulting PDS could only have 5
> members?
> ( or is that tracks > blocks and members are 5 to a block..)

Yes. The third value is number of blocks, which gives you on 
average about 4 members per block for a load module, and 
slightly more for source. The suggested space is adequate for 
the single module you were storing. If you will be testing and 
replacing modules, I'd suggest using SPACE=(CYL,(1,1,20)), which 
should suffice for a while - then you'll learn how to compress a 
PDS, allowing space to be reused. (Note that you'll need to 
delete and uncatalog the smaller instance before allocating the 
new one).

The DCB parameter is used to let the system and programs know 
what the format of the data is. For instance, compiler SYSIN 
data sets are "card" format RECFM=FB, LRECL=80, and the BLKSIZE 
is a multiple of 80 that's device dependent. For listings, IBM 
generally uses RECFM=FBA, LRECL=121, where the A means that each 
line has an ANSI carriage control (1=new page, blank=single 
space, 2=double space, minus=triple space, +=overprint); JES2 
printer length is 133. The DCB values, except block size, are 
fixed, and documented in the appropriate compiler's Programmer 
Reference manual, in the Utilities manual, and generally in the 
documentation describing a program. If your data and the program 
don't match, you may get incorrect output, or an error message, 
or abnormal termination.

Load module libraries are a special case - if you allocate the 
PDS without DCB parameters, the linkage editor will supply them. 
For general use and reduction of device dependence, I would 
suggest BLKSIZE=6144, as the 1024 size wastes an awful lot of 
disk space.

Gerhard Postpischil
Bradford, VT