Brian Howarth's Mysterious Adventures:
  --------------------------------------

  Since the Howarth data files are very closely related to the Scott Adams
  data files, it took me very few modifications to get them running with
  the standard adventure interpreter ADVENTUR/CMD, which can be found on
  many .DSK files containing Scott Adams Adventures.

  I had to do three modifications:

  1. I needed to reformat the datafiles found in the IF-Archives.
  (ftp://ftp.gmd.de/if-archive) Those are intended for the use with the
  Scottfree interpreter and have CHR 10 as a end-of-line marker. The
  TRS-80 needs CHR 13 as EOL, the Scott Adams database sometimes uses CHR
  10 inside strings as a LF. A small Pascal program did the trick for me.

  2. After copying the files to a virtual disk, ADVENTUR/CMD gave me first
  a "bad security" error message and returned to the Newdos prompt. This
  problem was a bit more complicated, but solvable thanks to the very
  detailed description of the Scott Adams format which comes with the
  "Adventure Editor" by Bruce Hansen and Allan Moluf. The program can be
  found on Ira's site. Apparantly the driver for the Howarth database does
  not use the security checksum which is necessary for the Adams driver.
  The three last lines in a database, which follow the remarks for the
  action table, give the version, the adventure number and the security
  checksum. The interpreter calculates an own checksum by adding the
  number of objects (line 2, counting from 1) and 2*number of actions
  (line 3) plus the version. If the number doesn't match with the number
  found in the database, the program simply stops. I was able to correct
  the checksums by hand, using a pocket calculator and an ascii-editor.
  (I really couldn't be bothered with writing a program for this little
  task :) )

  3. Another apparant difference between the Adams and the Howarth drivers
  is that the Adams driver needs information to allocate string space.
  Line 1 (counting from 1) in a database gives in KB the combined space
  needed for the text of verbs, nouns, messages, room descriptions and
  object descriptions. The Howarth databases contain a 0 at this position,
  therefore the Adams driver finds that it has allocated too little memory
  and drops out with an error message. Again, I was able to change the
  databases by hand, allocating about 6KB for each adventure which seems
  enough for the interpreter.

  I have quickly tried out every adventure and they seem to run perfectly
  well. I haven't played them through yet, so if anybody should have
  problems, I would be grateful if they contacted me at my momentary
  email-address (abels@stud-mailer.uni-marburg.de)

  Cheers and happy adventuring,

     Nele