The preferences dialog allows you to customize Gizmo for your particular system setup.  The options are as follows:

Auto-Scroll while converting, when enabled, will scroll the picture so that the current line that Gizmo is drawing will be in view.  Note that the image may scroll either up or down, depending if the picture is interlaced or not.  When disabled, no scrolling will occur.  Gizmo does not do any horizontal (left/right) scrolling, only vertical (up/down).

Auto-Size window on Open, if enabled, will size Gizmo's window to either the size of the picture being opened or to the size of your display - whichever is smaller.  On multi-display systems, Gizmo will re-size the window on the display that contains largest amount of its window area.  For instance, if Gizmo's window spans across two displays, the display that holds most of the window contents will be chosen as the target display for re-sizing.   When this option is disabled, no window sizing occurs.

Use sounds is a simple feature.  When a new picture is automatically opened or when a picture is finished being converted, Gizmo will beep.  If this feature is disabled, Gizmo will only make a sound when it needs to inform you of a problem.

Hand Grabber Refresh is used to increase performance while moving the picture around.  The Normal refresh is to redraw the entire window contents as the picture is moved.  This works very well on monochrome Systems or on color Systems in monochrome display mode (Black and White).  When moving the picture around in color mode, however, can slow things down a bit if the window and picture size are relatively large.  Under these circumstances, using the Delayed refresh option is recommended.  What happens is that Gizmo will move the picture around the screen - but the parts that need to be refreshed are drawn as "gray" - until you stop moving the picture.  This increases performance because Gizmo doesn't have to update the entire window each time the picture is moved a little.  Once you stop moving the picture, Gizmo will refresh the entire picture for you.  If you switch between color and monochrome mode often, you may want to use the Automatic refresh option.  This tells Gizmo to use whatever method is best depending on the current settings of your display (if in color mode, Delayed refresh is used - otherwise the Normal refresh method is used).

Window Position controls Gizmo's window position the next time Gizmo is opened.  Keep saved position means "don't touch the saved window position - leave it at whatever it was before".  This is always the default state, since it tells Gizmo not to change your window setting when saving your other Preferences settings.  Forget saved position tells Gizmo to forget whatever position is currently saved and go back to using the default window position (the position used when Gizmo shipped).  Save current position will save the current window position so it will be used the next time Gizmo is opened.  These setting only have an affect if the Preferences settings are Saved. 

PICT file creator is the application signature you want to use with the PICT files that Gizmo saves.  It must be four characters long or Gizmo won't let you save your settings.  This allows you to open the documents from the desktop to launch the appropriate graphics application.  Some examples are:  MacDraw (MDRW), PixelPaint (PPNT), and PhotoMac (PMAC).  Many others are listed in the documentation.

Screen Refresh Delay serves two purposes:  First, it can be used in conjunction with Gizmo's special interlace redraw to produce special animation with interlaced pictures.  It can also be used to increase performance when displaying pictures in color.  Since it takes a relatively long time to draw a single line of graphics to the screen, using this delay feature to cause the picture to be drawn in "chunks" can improve performance drastically.  For example, just using a refresh delay of five seconds can increase performance by 50% or more!  When the refresh delay is used, the only time Gizmo refreshes the display is when one the following occur:   The current image is done converting, the refresh time has elapsed, an interlace pass has completed, or the picture is moved with the hand grabber.  Acceptable values for this item are 0 (zero, no delay, draw line-by-line) to 60 seconds.  Depending on the speed of your System, 5 to 20 seconds are recommended.

Alternate GIF file name is for specifying a global alternate file name for Gizmo to search for when automatically opening GIF pictures.  The standard file name extension of ".GIF" is always searched for first.  You can enter a alternative in this field - up to sixteen characters, but it must contain at least two characters.  Gizmo doesn't check for the case of characters, so upper- and lower-case doesn't matter.  It also doesn't matter where in the file name the match occurs.  Since each Preset allows you to enter an alternate file name, there usually isn't a need to change this option too.  If you don't want to use this feature, leave it blank.  Example:  "GIF" will match "What is GIF?", "Porsche.gif", and "GIF Specification"; whereas ".GIF" would only match "Porsche.gif" in the preceding list.  NOTE:  It is possible to have three different searches for a GIF picture to open automatically:  the standard ".GIF" which is always searched for, this feature, and the Alternate Name in the Presets dialog.

Save will, of course, save all your changes made and Cancel will ignore them.  Help displays this dialog

For further information regarding the use of Gizmo and specific communications software, please consult the documentation.