IBM 1130 User Manual page 479

Section
Subsections
Page
60
20
I
20 03
Computational Subroutines You Are Unlikely To Use.
Let's take the example again of the disk used ex-
clusively for a large inventory file. You have elimi-
nated the compilers, the plotter subroutines, etc.
Is there anything else on this disk that you won't
need? Unless you have an unusual inventory system,
the answer is yes. Do the inventory programs re-
quire the computation of any sines, cosines, etc?
If
not, you may gain 7 sectors by deleting the trig-
onometric and logarithmic subroutines:
FSQR ESQR
FTANH ETANH
FATN EATN
FAXB EAXB
FEXP EEXP
FLN ELN
FSIN ESINE
Seldom-Used Programs and/or Data. Because the
1130 Monitor makes it so easy to do so, many people
tend to "overstore" the disk. This is particularly
true of programs, which are often *STOREd as a
matter of course, with no rules regarding what gets
*STOREd and what doesn't. As a practical matter,
however, many programs should not be placed on
the disk, but should be compiled each time they are
used. For example, suppose that program XYZ is
a stand-alone program that does nothing but read a
deck of cards and produce one or two pages of results.
It is run monthly, cons ists of 150 FORTRAN source
cards, and uses 2100 words of core storage. To
compile (without listing) and execute it, will take
about:
Compile
Execute
2 minutes
3 minutes
Total 5 minutes
To load it from the disk and execute it, will take
about:
Load
Execute
Total
1/2 minutes
3 minutes
3 1/2 minutes
By storing this program on the disk, you will
save 1 1/2 minutes per month, but will use 2100
words of disk storage, or about seven sectors.
Is it worth it? That depends on your installation.
If disk space is scarce, the answer is: "No -- don't
store it!"
If
there is plenty of room on the disk, the
answer is: "Yes, why not?"
Obviously, some programs should or must reside
on the disk:
- Often used subroutines and functions
- Programs called as LINKS by other programs
- Frequently used programs
- Very large programs
- Programs that are run with a series of other
programs, as one batch JOB.
Unneeded User-Written Programs and Data. This
usually applies more to programs than data. Over
a period of months, the typical disk becomes clut-
tered with numerous abandoned, obsolete, and/or
useless programs and SUbprograms. The LET /FLET
should be dumped periodically and inspected for such
items. Anything not really needed should be deleted.