Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!wuarchive!zaphod.mps.ohio-state.edu!usc!apple!agate!linus!linus!mwunix.mitre.org!twegner From: twegner@mwunix.mitre.org (Timothy Wegner) Newsgroups: comp.graphics Subject: Re: Viewer for GIF89a Message-ID: Date: 21 Sep 90 13:33:53 GMT References: <1990Sep17.200013.10204@cbnewsh.att.com> Sender: usenet@linus.mitre.org Distribution: usa Lines: 26 twb@cbnewsh.att.com (thomas.w.beattie) writes: >I have some .gif files in GIF89a format. >Cshow 8.11b 2/25/90 won't display them. >Is there a newer version of Cshow that supports 89a? >Would someone please upload it to Simtel or make it available for >anonymous FTP. >Anyone care to explain what is new and improved about GIF89a? and why it >isn't backward compatible? >--- The older CSHOW *should* display most GIF89a files. The new spec allows use of extension blocks to store comments and application-specific information. The previous spec (GIF87a) did not allow the use of these extension blocks but *DID* specify how to skip over them - thus any decoder which doesn't choke on the "89a" in the signature (as some do) should skip over the extension blocks and display the image justy fine. Some other enhancements include text display and timing parameters for images. FRACTINT version 14 creates GIF89a files - the older Cshow buzzes angrily and makes the "89a" flash on the screen - but then goes ahead and correctly decodes the image. The new Cshow is the only decoder to my knowledge that fully supports the new spec. Cshow can be downloaded from the Compuserve PICS forum - it is in lib 3. I believe the file is called "CSHOWA.ZIP" - might be "CSHOWA.EXE".