HP OpenVMS Systems

COBOL calling DECforms?

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The Question is:

 
We are OpenVMS V1.4 and DecForms V2.1. I enjoy
programming with DecForms most of the time but
I have a terrible time with data type conversion
between Cobol and Decforms. What works in one
program does not always work in another.
ex. PIC 9(4) comp in Cobol should be an unsigned
word in DecForms. This works in one program but not
another. I would love to have a conversion chart
from Cobol to Decforms. The Decforms documentation
is lacking. Thanks for your help, Chris
 

The Answer is :

 
  COBOL, in general, is one of the more difficult languages for making
  calls to external routines and system service routines among all of
  the available OpenVMS languages.
 
  Examples of COBOL calls to various routines and services are available
  via DSN (DSNlink), and via the customer support center.  Also see
  various previous discussions of COBOL here in Ask The Wizard. (At
  least one moderately-sized COBOL system service call has been posted
  here.)
 
  And as a general recommendation, learn the calling standard and the
  associated memory and argument passing, then -- secondary -- learn how
  the language(s) in use map to the calling standard.  Also learn how to
  use the OpenVMS debugger, as this allows you to directly examine memory
  and registers, and this can allow you to use your knowledge of the
  calling standard and your language(s) to determine why a particular
  call does (or does not) work.
 
  Once you become comfortable with the calling standard and with a few
  basic calls, you will find it far easier to generalize your knowledge
  and determine how to call a particular new routine...
 

  

     

     
answer written or last revised on ( 16-SEP-1998 )
     
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