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HP OpenVMS Systemsask the wizard |
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The Question is: While waiting for a response to my other question re: Compaq COBOL ACCEPT/DISPLAY fiasco I have another along the same lines. Why does the new DISPLAY not obey the VT200 save cursor and restore cursor escape sequence commands? If I issue DISPLAY "<ESC>7<ESC>[24;1HThis is a help line<ESC>8" then the cursor is placed at line 24 column 20 and is not returned to the last position it was called from. It seems to me that the DISPLAY should obey the save/restore cursor escape sequence s because it did obey the move to line 24 column 1. ...john The Answer is : As discussed previously, when using extended DISPLAY/ACCEPT capabilities, the COBOL Run-Time Library (RTL) uses the Screen Management (SMG) RTL, and SMG takes total control of the display. Escape and control sequences are explicitly and deliberately removed from the output stream to ensure that SMG knows precisely what the display looks like, and where the cursor is located at all times. The choice of the COBOL programmer is either to use the features of the COBOL ACCEPT/DISPLAY and accept that control of the display is entirely relinquished to COBOL, or to avoid use of the COBOL ACCEPT/DISPLAY extensions and manage the display directly via explicit escape and control sequences, or via explicit calls to the SMG, DECforms, FMS or other screen management package.
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