Before you can view pictures you must select one or more pictures from your disk or CDROM. You can view a single picture by using the “Open” action from the File menu, however the normal use of GIF Slideshow is to scan entire disks or CDROMs to find hundreds or thousands of pictures to be displayed.
Selecting pictures to be displayed
… Under System 7
Because of System 7’s “drag and drop” capabilities, GIF Slideshow is particularly easy to use. Simply drag the icons for one or more:
• GIF, TIFF, MacPaint or PICT picture files
• Folders containing any of the above
• Volumes (i.e. disks, CDROMs)
• Tag files created by GIF Slideshow
onto the GIF Slideshow icon (or its alias).
If the GIF Slideshow application is not yet executing it will start running. Then you will see a progress window indicating the name of the current picture that it has found, plus a count of the total number of pictures located so far. When all files/folders/volumes/tag files have been processed the first picture will be automatically displayed.
Once you have finished viewing a sequence of pictures you can view more by simply dragging and dropping more icons onto the GIF Slideshow application icon. You do not need to “quit” from GIF Slideshow to do this. Alternatively, you can open tag files or scan folders from within the application as described below under “System 6”.
If “dragging and dropping” doesn’t work …
If you cannot “drag and drop” files onto the GIF Slideshow icon, or if the GIF Slideshow application does not have a distinctive coloured icon, then you may need to rebuild your desktop so that the Mac recognises the new icon.
To do this, restart your Mac, holding down the Command and Option keys. When asked whether you want to rebuild your desktop, click OK.
… Under System 6
• If you have previously created a “tag file” from within GIF Slideshow you can just double-click (open) this file and the GIF Slideshow will commence running, and then display all the files listed in that tag file.
• Otherwise, double-click on the GIF Slideshow to open the application, and then use the “File” menu to either open a tag file (Command-O) or scan a folder (Command-S).
To scan a folder, type Command-S (or select “Scan folder” from the File menu), and then use the dialogue box to open any file in the desired starting folder. GIF Slideshow will then read into memory the names of all GIF pictures found in that folder, and all sub-folders below that folder, and then commence showing the first picture. As the entire folder is scanned it does not matter which file you select to start with—it is merely a starting point for the scan.
Scanning time
Time taken to scan folders
Scanning a folder on a hard disk is very fast. You can expect to take about 2 seconds to scan a folder with over 100 files in it. However scanning an entire volume can be somewhat slower, as the application has to examine every file to see if it might be a GIF picture. As a guide, the author’s 100 Mb hard disk took 47 seconds to scan. Scanning an entire CDROM can take correspondingly longer (CDROMs usually contain 600 Mb of data), particularly if it is a Mac CDROM with many sub-folders in it. Users are strongly advised to create “Tag files” of their CDROMs which, once initially created, are much faster to process.
Time taken to scan CDROMs
As an example, the author extracted the following times using a Mac IIci processing the “GIFs Galore” CDROM from Walnut Creek, 1st edition. This CDROM has 6,483 GIF pictures on it.
Initial scan of CDROM:
9 minutes 30 seconds (do this once only, to find all the picture names)
Writing tag file:
1 minute (do this once only, to create the tag file)
Reading tag file:
14 seconds (do this in the future to view the pictures on the CDROM)
As you can see, it is over 40 times as fast to read the tag file (which already has all the GIF picture names and folder codes in it), than to scan the CDROM directly.
