Life in high rez

[FORTRANS]

the big issue, back then, was variations in the chip-sets
there were a half-dozen or so chip-sets in wide use, and some paged a little differently

Hi,

   Yeah, the granularity in the code above was for a western Digital
card with 4k granularity.  Most everything now is 64K.  And some cards
supported 2 windows into the video memory.  The one I am working
on now only has one.  Makes moving things around a pain.  64k windows
with 64k granularity sort of negates any usefulness of that feature.

Regards,

Steve N.

[Magnum]

I see by the code that it's a lot of work setting up Vesa modes.

Since they had Vesa for so long, is the reason there was so little 16 bit code written for it is cuz of the "un-standardized" video cards ?

Andy

[FORTRANS]

Hi,

   It is not hard to set a VESA mode.  It is not hard to do some
things in that mode.  But some things are very hard to do due to
the screen being composed of many banks of video memory.
You cannot count on accessing more than one bank at a time.
And you have to cope with non-overlapping windows with most
cards.

   So, there is little difference in an animated GIF display program
between the Mode 13H VGA and teh MODE 111H VESA implementations.

08-02-02  02:10p                26,963 GIF13T.EXE
08-02-02  12:36p                28,257 GIF111T.EXE

   However the Mode 13H and Mode 101H star field or coral snake
demos I have posted show a different story.

24-07-13  11:53a                   863 STARSGAM.COM
21-08-13  01:21p                 5,109 STARSGAM.EXE

   There was a fair amount of 16-bit VESA code written.  But
Windows and Linux sort of squashed all of that.  LxPic is a
capable picture viewing program for instance.  Supports thumbnails,
slide shows, and varying the image contrast among other things.

DOS Palmtop Freeware

Cheers,

Steve N.

[goofprog]

Oops.

I got this message. "NTVDM CPU has encountered an illegal instruction."

cs:0000 ip:01a3 op:f0 4e 67 00 f0
Choose close to terminate app.

I am thinking this is not compatible with the Vesa mode 101 part of the code.

Code Select Expand


            push 0A000h             ;ES = video memory
            pop es

Nope.  I think you are using an operating system greater than Windows XP.  I get this message in Windows Vista.  I think that the OS does not like to support those video modes anymore.  I tried to use an old 16bit DOS app and it says that 16bit applications are not supported in console mode.   It looks that the only way to work around it is to use a virtual machine.  Try virtualbox and build MS-DOS or maybe a Windows XP box from that and try it.

[Magnum]

Thanks.