Dead thread, I know, but for anyone interested, DOSbox does record AVI video, and that can be converted to Gif by some tools; and/or extracted to frames by other tools.
Example: Phlan Deluge
Six frames/color changes. Recorded in DOSbox, I used Jasc Animation-Shop to make it a Gif,
but VirtualDub could also have exported a Gif, and Irfanview could have extracted the frames for use in other tools.
The advantage of Animation-Shop is that it will evaluate the frame intervals when it imports the AVI.