cim1@pyuxv.UUCP (G. Bogatko) (11/05/85)
When resetting the PC cursor, one thing must be kept in mind: There are two cursor sizes. One for the monochrome display, and one for the color display. The cursor for the monochrome starts with line 0 at the top and ends at 13 on the bottom. The cursor for the color starts with 0 at the top and ends with 7 at the bottom. When setting the cursor size, a check must first be made to see what kind of card is installed. Calling int 10 with AH set to 15 will return a value in AL of either 0-3 if a color card is installed, or 7 if a monochrome card is installed. If this check is not made, setting the color cursor to 5,6 for instance which is the normal color blinking underline, will set the monochrome cursor to a thin line somewhere in the middle of a character rather than the normal 12,13 setting. Trying to set a full size cursor, say 0,7 on color will obtain a half-size block at the top of the line on monochrome rather than the full block (setting 0,13) that it should be. By the way, this same kind of check should be made when doing direct screen access to make sure you are writing to the correct area. Hope this helps. G. Bogatko