Q58792: PCOPY Can Fail from Page 0 in 43-Line Mode in SCREEN 0
Article: Q58792 Product(s): See article Version(s): 7.00 Operating System(s): MS-DOS Keyword(s): ENDUSER | SR# S900214-56 buglist7.00 fixlist7.10 | mspl13_basic Last Modified: 6-AUG-1990 In Microsoft BASIC Professional Development System (PDS) version 7.00, when in 43-line mode in SCREEN mode 0, using a PCOPY statement to copy screen page 0 to some other screen page may fail. If screen page 0 is both the visual and active page during the PCOPY statement, it copies corrupt information to the other screen page. This problem occurs only in SCREEN mode 0 when in 43-line mode and only when PCOPYing from page 0. It does not occur when PCOPYing from another page to page 0. Temporarily setting the active and/or visual page to a screen page other than 0 during the PCOPY corrects the problem. Microsoft has confirmed this to be a problem in Microsoft BASIC PDS version 7.00 for MS-DOS. This problem was corrected in BASIC PDS version 7.10. The following program demonstrates the problem. A string of 3440 X's that fills the screen is displayed, then copied from page 0 to page 1. The visual page is then set to page 1 to view the information copied from page 0. What appears in page 1 is only a few lines of text, either at the top or middle of the screen. Setting either the visual and/or active screen page to any page other than page 0 corrects the problem. WIDTH 80, 43 PRINT STRING$(3440, "X"); 'SCREEN , ,0, 1 'Uncommenting this line corrects the problem PCOPY 0, 1 LOCATE 10, 10: PRINT " HIT ANY KEY TO SWITCH PAGES " SLEEP SCREEN , ,0, 1 END
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