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HP OpenVMS Systemsask the wizard |
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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...
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