USER GRIDS
           ORDNANCE SURVEY OF GREAT BRITAIN
                    (2 March 2004)

Dominic Sexton <grid@dscs.demon.co.uk> and
Dave Martindale davem@cs.ubc.ca write:

You can setup a User Grid with the parameters of the OS grid.
Long of origin:   W 2 degrees
Scale:            0.9996013
False Easting:    400000m
False Northing:   -5527064m
Datum:            Ord Srvy GB (Ordnance Survey of Great Britain)            

**Important note for Garmin users of older units, remember this!

Some older Garmin units do not have enough character positions to enter
a false northing of -5527064 complete with minus sign.  With them, you
can use a false northing of 4472936 instead.  This gives a "Y" value
that is 10 million meters too large, but these same Garmin units only
display 7 digits of northing so the leading "1" is lost and you get the
correct Y value after all.