boozer@leedat.UUCP (G. Boozer) (02/17/90)
When I switch to 43 line mode on an EGA system, I loose the cursor.
I need an ansi.sys driver that can do this or I need a program that
switches into the 43 line mode and fixes the cursor.
Could you offer any recomemdations?
Thanks,
Glenn Boozer
Lee Data Corp, Networking Div.
{decwrl|ames}!mips!leedat!boozerTRL3@psuvm.psu.edu (Tim Larson) (02/18/90)
Sorry to post rather than mail, but my mail to the original poster bounced. This subject may be of general interest anyway. The original post asked why the cursor disappeared after switching the EGA to 43 line mode. On the EGA, cursor emulation is implemented by adding 5 to any Cursor Start or Cursor End value greater than 4 (since the original character matrix was 8 lines high, but the EGA is 14, this provided compatability with old CGA software). However, you are changing the character matrix back to 8 lines high, so simply disabling cursor emulation should work. Change bit 0 of the Video Display Data Area INFO byte (0040:0087) to 1 (leaving other bits unchanged) *before* calling INT 10H function 01H. By the way, the VGA takes the character height into account, so this information is EGA-specific. (Source: "Programmer's Guide to PC & PS/2 Video Systems," Richard Wilton, [Redmond, WA: Microsoft Press], 1987. An excellent book, BTW :)) Cheers! -Tim Larson trl3@psuvm.bitnet