dispcor
        input = input list      List of input spectra
       output = output list     List of output spectra
   (linearize = yes)            Linearize (interpolate) spectra?
    (database = "database")     Dispersion solution database
       (table = "")             Wavelength table for apertures
          (w1 = think)          Starting wavelength
          (w2 = think)          Ending wavelength
          (dw = INDEF)          Wavelength interval per pixel
          (nw = same as input)  Number of output pixels
         (log = no)             Logarithmic wavelength scale?
        (flux = yes)            Conserve flux?
    (samedisp = no)             Same dispersion in all apertures?
      (global = yes)            Apply global defaults?
   (ignoreaps = no)             Ignore apertures?
     (confirm = no)             Confirm dispersion coordinates?
    (listonly = no)             List the dispersion coordinates only?
     (verbose = yes)            Print linear dispersion assignments?
     (logfile = "dispcor.log")  Log file
        (mode = "ql")           

CAUTION:

The data are  changed irreversibly in this step. You should
protect the original data by writing the result into output
files that are different from the input files.

General Philosophy

Try to deviate from the original wavelength scale as little 
as possible. But at the same time you should also to give 
all the spectra the same wavelength scale (i.e., same starting
and ending wavelengths and number of pixels). This makes life
a whole lot easier in later steps. But before you can choose
a single wavelength scale that will apply to all spectra and
conform to the above philosophy, you have to know the starting
and ending wavelengths corresponding to each spectrum.

In Practice

Make a first pass with dispcor with the following parameters:

linearize = no
         ...
       w1 = INDEF
       w2 = INDEF
       dw = INDEF
       nw = 1190 (i.e. the same number as the original spectra)
         ...
 listonly = yes (this will list the solution but not apply it)

The idea here is to get a list of the starting and ending 
wavelengths of each sepctrum so that you can choose global
starting and ending wavelengths, common to all spectra. 

Then make a second pass with the parameters set as follows:

linearize = yes
         ...
       w1 = whatever value you chose
       w2 = whatever value you chose
       dw = INDEF
       nw = 1190 (i.e. the same number as the original spectra)
         ...
 listonly = no (this will list the solution but not apply it)

In the second pass dispcor will apply the solution and resample
the spectra to a linear wavelength scale. Moreover it will give 
all spectra the same starting and ending wavelengths and the same 
number of pixels (i.e., the same wavelength scale)