15.64.31.23  Restrictions   - The  maximum  number  of  histograms you may
restore is 499.  The maximum memory for HBOOK histograms is 150,000 words.
(1.2 Mbyte)  The  maximum  title  length is 256 characters.  If you have a
file  exceeding  these  restrictions  you  must  restore  each   histogram
individually by:
     TD:SET HISTOGRAM HBOOK FILE=name ID=n