GRASS and HP RTL

[N R A]

I've found out that our Novajet plotter also accepts 'HP RTL' which I 
presume is Hewett Packard's format for raster images - can anyone tell me 
more about 'RTL' and especially is there any documentation available - 
I'm interested in developing a driver for GRASS to plot to the Novajet.

Thanks for any help,

Steve Culshaw
NRA North West
e-mail : nra at cix.compulink.co.uk (general usage)
or         sculshaw at cix.compulink.co.uk (Private - only checked at best 
weekly)