Run length rasters?

[David Riches]

I have a number of Sun rasterfiles which I want to look at.  Using
screenload I can look at some of them but not all of them.  The ones that
I can't look at are run-length byte encoded images.  I use a Sun 3/50/60
with SOS 3.4

Now if I use a colour sun running 4.0 then I can look at all of the
images.  Does any one know why I can't on the mono 3/50's?

   Dave Riches
   PSS:    dsr at stl.stc.co.uk
   ARPA:   dsr%stl.stc.co.uk at earn-relay.ac.uk
   Smail:  Software Design Centre, STC Technology Ltd., London Road,
	   Harlow, Essex. CM17 9NA.  England
   Phone:  +44 (0)279-29531 x2496