mrk@gvgspd.UUCP (Michael R. Kesti) (10/12/87)
I downloaded PC Magazine's SNIPPER (Vol 6, No. 18) last night, and was quite surprised to find that it wouldn't work properly on my AT&T 6300. It didn't respond to the down arrow key at all, and the up arrow key sent the cursor to obvlivion. I was able to trace the problem to the initialization of the ROWS variable, which this program stores at 40:84. According to the magazine article, this location holds the number of display rows available if an EGA is used, or zero for all other display adapters. The initialization code reads this location and, if it is non-zero assumes that an EGA is present and leaves it alone; otherwise it writes the value 24 (decimal) there, under the assumption that a CGA or MDA is present. On my machine this location holds the value 0xCE (206 decimal), and so is not changed. Needless to say, my display does not have 206 rows, and this explains the programs behavior. BTW, I run DOS v2.11 and ROMs v1.00 (I know, I should upgrade both of these, but I have never had a compelling reason to do so; maybe I do now?!?) and use a color monitor. Well, I altered the program to use ROWS=24 at all times, and viola, it works as advertised. My questions: For what is my system using this location? What other low memory suprises might be lurking around in there? Any enlightenment will be appreciated and, as they say, thanks in advance. -- =================================================================== Michael Kesti Grass Valley Group, Inc. P.O. Box 1114 Grass Valley, CA 95945 UUCP: ...!tektronix!gvgpsa!gvgspd!mrk