GIF Blast is a compressor designed especially for GIF files. The usual file compressors do not work on GIF files; GIF Blast does. GIF files are compressed to so-called GFB files that are usually 27…33% smaller.
Shareware notice
This Macintosh version of GIF Blast is shareware. If you find you are still using this program after 15 days, you must send me a shareware registration fee for US$ 10, or 15 Dutch guilders (if you live in Europe, you can send a eurocheque instead of cash).
Eric Toonen
P.O. Box 616
5600 AP Eindhoven
The Netherlands
About compressing GIF files
GIF Blast is recommended for applications such as storing GIF files on BBS’s and posting GIF files to Usenet.
Because GIF Blast perfectly preserves all images and other information in GIF files, the user need not be concerned with harming the images.
The compression/decompression algorithm used in GIF Blast is quite slow, so you would probably not want to store frequently viewed GIF files in compressed form. However, GIF Blast should be useful in applications where getting maximum compression is important, such as:
- Storing GIF files on bulletin boards for downloading.
- Posting GIF files on usenet.
- Transmitting GIF files via modem.
- Sending GIF files on floppy disk.
You may notice that a compressed and decompressed GIF file is not always byte-for-byte identical to the original GIF file. This is nothing to worry about, and the GIF images are not changed at all. The GIF standard allows some variation in how images are encoded, so an identical image can be encoded as two different GIF files. This is what is happening in this case. If you want to confirm for yourself that the GIF images are not affected, convert both files to an uncompressed format such as TIFF and compare them.
How to use GIF Blast
(Balloon help is available in all menus.)
You can use GIF Blast in two ways:
1. As a simple application. Double click the GIF Blast icon and use “Open…” from the File menu to open (and convert) GIFs to GFBs or GFBs to GIFs.
2. In system 7.0 or later only: As a drop application. Drag and drop a (group of) GIF file(s) on GIF Blast to automatically compress it/them. If you drop GFB files, they will be decompressed.
To compress GIF files, either:
• Drag and drop a (group of) GIF file(s) on the GIF Blast icon, and they will all be compressed to GFB. Or,
• Launch GIF Blast, use ‘Open…’ from the File menu to open a GIF file, which will be compressed to GFB.
To decompress GFB files, either:
• Double click on the GBF file(s), and they will all be decompressed to GIF. Or,
• Drag and drop a (group of) GFB file(s) on the GIF Blast icon, and they will all be decompressed to GIF. Or,
• Launch GIF Blast, use ‘Open…’ from the File menu to open a GFB file and it will be decompressed to GIF.
Options
You can set several options:
• When you check “Open Any .GFB File”, the ‘Open…’ dialog will contain all files who’se names end in “.GFB” or “.gfb”. If this option is unchecked, the dialog will only contain GFB files that were created by Macintosh GIF Blast.
• When you check “Ask Target Name”, after you open (or drop) a file, a standard ‘Put file’ dialog appears that allows you to change the generated name and folder to place the converted file. If this option is unchecked, GIF Blast generates a file name, and places the converted file in the same folder as the original.
Note: when “Ask Target Name” is checked, you cannot drop multiple files if GIF Blast is already launched.
• When you check “Overwrite”, files with the same name as the target will be overwritten without warning. If this option is unchecked, an error alert will be displayed instead. This option is unavailable when “Ask Target Name” is checked, because it will ask whether or not you want to replace an existing file.
• When you check “Remove Original”, the original file(s) will automatically be removed after the conversion (either compression or decompression) is done.
• When you check “Quit After Drag&Drop”, GIF Blast will automatically quit when it was launched by dropping files.
• You can select your favourite application in the ‘Create GIFs For’ submenu. When a GIF is created from a GFB, the selected application will be designated as the owner of the GIF.
• You can select which version of GFB files are created when GIF files are compressed. Version 1.1 is compatible with the old MS-DOS version 1.1 of GIF Blast. Version 2.0 compression is better, though. More compatibility issues are discussed later in this text.
• ‘Save As Defaults’ (in the Options menu) saves the current options and window position to the Preferences file, so they will be used as defaults the next time you use GIF Blast. The preferences file is created in the preferences folder (System 7) or System folder (System 6).
• ‘Revert To Saved’ (in the Options menu) reads the options and window position from the Preferences file.
Backgrounding
GIF Blast can do conversions in the background (in System 7 or when you’re using Multifinder under System 6). While GIF Blast is converting files, you can switch to any other application or the Finder.
Notification: When GIF Blast needs attention (because an error occured or you have to type a target filename), the GIF Blast icon will blink on top of the ‘Application’ menu (System 7) or Apple menu (System 6). And the GIF Blast application will be marked.
Preview icon
If your GIF files have a “preview icon”, it is copied by GIF Blast to the GFB file (and back again).
‘Preview icons’ are custom icons for System 7, created by Thumbnail or by Adobe Photoshop if “Save preview icons” in the General Preferences is checked.
Compatibility with MS-DOS
This Macintosh version of GIF Blast is compatible with the MS-DOS versions 1.1 and 2.0 by Isaac Dimitrovsky. It can read GFB files created by either MS-DOS version. It can write both version 1.1 and 2.0, as specified in the ‘Options’ menu.
GIF Blast does not support version 3.0 which was promised by Isaac Dimitrovsky, but which I haven’t seen.
If you use software to read MS-DOS disks, such as PC-Exchange, AccessPC or DOS-Mounter, don’t forget to have it automatically recognize file-extension “.GFB” and map it to Creator “MGFB” and Filetype “GFBf”.
To order the MS-DOS version of GIF Blast, make a $20 check payable to Isaac Dimitrovsky Labs and send it to:
Isaac Dimitrovsky Labs, 147 Second Ave #484, New York NY 10003. Be sure to include a full return address, and specify 3.5 or 5.25 inch disks.
Remember that I (Eric Toonen) have nothing to do with Isaac Dimitrovsky. Nor has Isaac Dimitrovsky anything to do with the Macintosh version of GIF Blast (apart from the fact that part of his free code was used in this application).
I want your help!
Do you frequently use other applications than GIFConverter or Adobe Photoshop to read GIF files? Send me the Icon-family for the GIF-file created by that application, some information on the application (who wrote it, where can I find it, its full name) and the Creator signature.
My Internet E-mail address: eric@djoe.iaf.nl
On CompuServe: >INTERNET:eric@djoe.iaf.nl
Fidonet: 2:284/406 ‘Eric Toonen’.
Dutch 27MC Packet radio: DR3LLA@NL3EHV
My normal address is:
Eric Toonen
P.O. Box 616
5600 AP Eindhoven
The Netherlands
Technical details
There is no difference between GIFs created for different applications, such as ‘Adobe Photoshop’ or ‘GIFConverter’. The only difference is in the Creator (signature) for the written GIF file. You can drop or open any GIF file with either of these applications. GIF files are of type ‘GIFf’. GFB files are of type ‘GFBf’.
You can patch ZTerm 0.9 to automatically set the correct Type/Creator upon receiving GFB files from a Bulletin Board System:
- Open ZTerm with ResEdit
- Add a “GFBf” string to STR# ID=330
- Add a “0MGFBGFBfGB” string to STR# ID=335
- Save ZTerm
- Quit ResEdit
Version 2.0 of GIF Blast was created using Think C 5.0.4 on a Macintosh LC II.
It requires a Mac Plus or better, system 6.0.4 or higher (System 7 needed for drag&drop and balloon help), 400 Kb RAM.
Tested on:
- Mac LC II (or Performa 400) with system 7.1 english
- Mac Classic with system 7.1 hungarian
- Mac Classic II (or Performa 200) with system 7.1 dutch
Version history
2.0.5 • Preferences now in resource
• ‘About’ now has scrollable help
• Can write v1.1 GFBs
2.0.4 • Copy possible preview icon
2.0.3 • Stop button
• Can background
• Can ‘Open…’ while converting
• Window pos in pref file
• Can have ‘Other’ GIF owner
2.0.2 • Optionally ask for target name, possibly replace
• Options in preference file
2.0.1 • Allow user to open any file ending in .GFB
I would like to thank Maarten Los for his help on this product.
Small print
The Graphics Interchange Format is the Copyright property of CompuServe Incorporated. GIF is a Service Mark property of CompuServe Incorporated.
Apple, MultiFinder and Macintosh are registered trademarks and Balloon help, Performa and Finder are trademarks of Apple Computer, Inc. Adobe is a registered trademark and Adobe Photoshop is a trademark of Adobe Systems Incorporated. MS-DOS is a registered trademark of Microsoft Corporation. Think C is a trademark of Symantec Corporation.
