Technical notes on WInfocom (this document is in writing, and not complete
  yet):

  Implementation: WInfocom was written using Borland C++ 3.1. The OWL
  Windows class was used for easier programming.
  As stated in the README file, WInfocom uses Mark Howell's ZIP interpeter.
  ZIP (no relation to PKZIP), by the way, is "Zork Interpertation Program",
  meaning the program that can run Z-code, Z-code being the `assembly
  language' in which Infocom games are written. If you are a regular reader
  of rec.arts.int-fiction, you probably knew that already.

  Fonts: Infocom games consist of two areas. The text window holds the
  regular messages, and the status window holds status information (current
  location, moves and so on), and in the newer games (called V4 games), all
  other kinds of stuff, like the messages in Trinity or the `forms' in
  Bureaucracy. The cursor can move freely in the status window, but is
  limited to TTY-style movement (that is, the cursor cannot be moved; it
  only advances when characters are written) in the text window.
  Since the status window often holds table-arranged information like menus,
  the font used in it is fixed-pitch (the width of the letters in the same
  for all letters), while the text window uses the more comfortable
  proportional font (each letter has its own width; `i' is narrower than `m').
 
  Scrolling: WInfocom uses the standard Windows function ScrollWindow to
  scroll it output. This function is smart enough to handle obscured text
  (text that is not fully shown on the screen), but when obscured text is
  scrolled, it has to be repainted, result in slower scrolling.
  Text can be obscured either by the bottom of the window (i.e., the window
  is not large enough to hold all of the text), or by another window. The
  latter can only be caused under Windows 3.1, in which a window can be set
  to be "Always on top" (the Clock has such an option, for example). In that
  case, that window will obscure any other window. Therefore, it is
  recomended for speed reasons that the user will always size the WInfocom
  window to show the full text (or if not possible, always scroll to the
  BOTTOM of the window), and not cover WInfocom by "Always on top" windows.

  Beyond Zork and the graphics: The `graphics' in Beyond Zork is not really
  graphics; instead, the game uses a special font with graphic patterns
  instead of letters (similiar in essence to the Symbol and Wingdings fonts
  that come with Windows). In the IBM PC version of the game, the font comes
  in at the end of the data file, in a simple format very suited for the CGA
  adapter games were run on. The font contains characters 32-127, each
  character taking 8 bytes, for a total of 768 bytes. All the MAKEFONT
  does is read the last 768 bytes from the data file, and write them in the
  font file with the appropriate header (actually, it also doubles the font's
  height by writing each byte twice).