From kragen@dnaco.net Thu Jul 23 12:59:45 1998 -0400 Date: Thu, 23 Jul 1998 12:59:44 -0400 (EDT) From: Kragen To: fractdev@xmission.com cc: linux-msdos@vger.rutgers.edu Subject: Fractint in dosemu Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Keywords: X-UID: 711 Status: O X-Status: I'm running Fractint 19.5 in dosemu 0.66.7 (under Caldera OpenDOS 7.01) in XFree86 3.3.2 on Linux 2.0.30 on an AMD 5x86-133. I'm liking it very much! Now I can do fractals in a window while I'm analyzing data, reading my email, or whatever. But there are some problems with it. I think most of these are problems with dosemu; I wonder if some of them could be worked around in Fractint without any difficulty? I hope this message is interesting to some of the fractint developers. I'm sure it will be to the dosemu developers. - When I select 800x600x256 from the DEL screen, it works properly, and dosemu says: vesa_set_SVGA_mode(): mode=0x5e. But if I TAB to the info screen, then hit TAB again to get back to the picture, it doesn't print that message, and it also doesn't redisplay the picture. It looks like it's displaying the first few pixels of the image as text, though -- my screen fills with multicolored blocks of characters. (Screenshots upon request.) Switching back and forth works fine at 320x200x256. I have the same problem with some other VESA modes, too. Maybe it's universal to all of them. The blocks of characters also appear momentarily switching from the image to a text screen -- for example, when I hit 'T'. - Sometimes Fractint seems to hang. If I hit Esc a couple of times, I can get to a menu and a sensible state, but if I'm in a VESA mode, of course I've lost my fractal. I suspect Fractint is trying to do something, but I'm not seeing what it's doing due to some flaw in dosemu. - Sometimes, in VESA mode, solid-guessing doesn't fill in the solids on some lines. I'll see a fractal with big black cracks across it, with dots scattered in the cracks. The cracks go away on later iterations; I mention this because it might be of help with other problems. - color-cycling doesn't work. plasma displays with the default VGA colormap, and thus looks terrible. This is obviously not fractint's fault -- right? - Sometimes, when zooming in (even in 320x200x256), my zoom box gets filled with black. This makes it hard to zoom. Also, when TABbing back and forth on some bifurcation fractals, what was previously drawn gets erased -- it's displayed for a brief moment when returning to the picture, then the whole screen becomes black, then the fractal continues drawing from the right edge of what was previously drawn. This happens, for example, during the first zoom in basic.key. - Drawing an "icons" fractal after a "mandel" fractal at 320x200x256, the top and bottom of the "mandel" fractal (above and below where the "icons" fractal appears) remain on the screen. The same is true of running "diffusion" or "lsystem", or running "ant" after "plasma", or even "ant" after "ant". I suspect it's a general problem erasing the screen. (In fact, when zooming in on a "mandel" in solid-guessing mode, the old image is progressively erased as the new image is drawn. I initially thought this was a clever new feature.) - When I try the 1280x1024x256 VESA mode, Fractint says it's not supported with my adapter. - lsystem doesn't seem to work well at all in the VESA modes. It looks like fractint first switches to the VESA video mode, then switches back to text-mode to display the L-System thinking message, then fails the same way coming back from TAB or F1 fails. OTOH, it works pretty well with the MCGA mode. *sigh* - When saving an image (in MCGA mode), the text message that normally appears in the upper-left-hand corner of the screen when it finishes is only one pixel high, and the rest of that scan line turns to black. - Fractint consistently crashed dosemu during the demo: ERROR: unexpected CPU exception 0x06 errorcode: 0x00000000 while in vm86 (DOS) Program=sigsegv.c, Line=230 EIP: 0000:0000008d ESP: 4363:0000f032 VFLAGS(b): 00000 00110000 10000110 EAX: 00004201 EBX: 000099fe ECX: 000007cc EDX: 00000000 VFLAGS(h): 00003086 ESI: 00000012 EDI: 0000f52c EBP: 0000f44a DS: 4363 ES: 4363 FS: 0000 GS: 0000 FLAGS: PF SF IF RF VM IOPL: 3 STACK: 00 00 f8 bf 00 00 00 00 00 00 -> 00 42 91 0c f1 0c 46 32 c2 15 OPS : 01 39 10 00 01 26 01 d2 0a ca -> 26 8e 37 1c 01 d2 0a 41 10 00 Just after successfully loading new19001.gif. (in new19.key.) To reproduce: run demo.bat, select option 2, and wait. I think this happens every time you try to browse images (with "L"). I seem to remember that this used to crash the computer in real MS-DOS as well. Running fractint, hitting F3, and typing "L" makes it crash, too (in dosemu, that is). Sometimes it crashes with different register values. Anyway, I'm looking forward to looking at all the fractint list formulas and pars with my nifty new toy. :) Kragen