Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!think.com!spool.mu.edu!uunet!comp.vuw.ac.nz!cavebbs!frank From: frank@cavebbs.gen.nz (Frank van der Hulst) Newsgroups: comp.os.msdos.programmer Subject: Re: Hercules graphics with Turbo C and Debugger Message-ID: <1991Jun02.072332.27220@cavebbs.gen.nz> Date: 2 Jun 91 07:23:32 GMT Article-I.D.: cavebbs.1991Jun02.072332.27220 References: <009497E5.514A35E0@MAPLE.CIRCA.UFL.EDU> Organization: The Cave MegaBBS, Public Access Usenet, Wellington, NZ Lines: 27 In article <009497E5.514A35E0@MAPLE.CIRCA.UFL.EDU> sorrow@oak.circa.ufl.edu writes: >In article , Jari.Karjala@niksula.hut.fi writes: >|> >|>When I set the graphics mode through BGI's initgraph() function, I can >|>singlestep through the following code with Turbo Debugger and the >|>graphics/text screen is flipped correctly. But if I replace the >|>initgraph() with my own function to set the graphics mode (and don't >|>link with graphics.lib), TD no longer notices the mode change and >|>thinks it is still in text mode (and of course the result is not very >| >|> >|>The question is: what does initgraph do to tell TD that now we are >|>in graphics mode? Or is there some hidden function in the BGI library >|>which is used by the debugger? I've got code which switches a VGA into 320*400*256 colour mode. TC's integrated debugger certainly recognises that it's in graphics mode, although it treats it as if it was in 320*200 mode. That's not unreasonable, since the way I enter the graphics mode is to switch to 320*200 via BIOS call, then twiddle some VGA registers. Sooo... How are you switching to graphics mode? By calling INT 10h, or by changing some registers on your Herc card directly? -- Take a walk on the wild side, and I don't mean the Milford Track. Kayaking: The art of appearing to want to go where your boat is taking you.