I would have bet a lot of money that someone would recommend delaying the snapshot long
enough to revert to the Alt-F1 screen so /dev/fb0 would refer to the proper screen. That
does give me a nice 3MB or so raw file which can be converted to .png as follows:
iraw2png 1024 768 < screenshot.raw > screenshot.png
I tried fbdump --help but apparently I don't have that on my Slack 13.37 64 bit system.
I was under the impression that there were several /dev/fb's since multi-screen comfigurations
are possible but in /dev there is only one; fb0. Apparently multi-screen is only available
in xorg with a xorg.conf file altered to indicate multiple screens. Kind of makes me wonder
just what difference there is between /dev/vcs1... and /dev/fb0. Only /dev/fb0 will get
you a raw screen dump whereas /dev/vcs... will only get a text representation of the
screen and no graphics.