This file contains a look-up table to emulate the distance computations of HOST.EXE. Programs should use it to deliver exact predictions. See <http://phost.de/~stefan/fuelusage.html> for details. The idea is to compute 'Trunc(dx^2 + dy^2)'. HOST.EXE has some math errors here making it hard to duplicate its behaviour easily.
The file consists of 168 "rows" corresponding to dy values from 1 to 168. Each row consists of 21 bytes (168 bits) corresponding to dx values from 0 to 167. The low-order bit corresponds to the lower-valued dx. To compute the value 'Trunc(dx^2 + dy^2)', take the first dx bits in row dy, count the '1' bits, and add dy-1.
If either dx or dy is negative, remove the sign; if dy is zero, swap dx and dy (for dx=dy=0, the result is obviously zero). HOST.EXE never plugs values larger than 162 into the fuel formula.