TOPIC
This article describes a stability issue with the CFM-68K Runtime Enabler and 680x0 processor based Macintosh computers. There is also a series of related questions and answers.
DISCUSSION
Apple recommends customers upgrade to CFM-68K Runtime Enabler extension version 4.0. CFM-68K Runtime Enabler is available from Apple Software Updates. Apple Computer discovered a bug in earlier versions of the CFM-68K Runtime Enabler extension that affects the stability of Macintosh computers based on the 680x0 processor. Version 4.0 of the CFM-68K Runtime Enabler extension addresses this issue. This extension allows the use of certain applications on 680x0 computers, and is installed by an application installer only if the application requires the extension. Customers will know they have this extension installed if the file " CFM-68K Runtime Enabler" (note that the file name begins with a space) is located in their Extensions folder which resides inside their System folder. In certain circumstances, the bug could cause applications which rely on the CFM-68K Runtime Enabler to not function properly, resulting in application instability and potential loss of data.The most obvious symptoms are what appear to be random system crashes and hangs. Macintosh and Mac OS-compatible computers based on the PowerPC processor are not affected by this bug. Because of the potential quality impact of this bug, Apple is recommending that customers with computers based on the 680x0 processor upgrade to version 4.0 of the CFM-68K Runtime Enabler extension What is the CFM-68K Runtime Enabler? The CFM-68K Runtime Enabler is an extension which makes it easier for developers of applications to design their programs to run on both 680x0 and PowerPC computers without having to write separate programs for both processor families. On a more technical level, the Code Fragment Manager ("CFM") was originally introduced by Apple only for Macintosh and Mac OS-compatible computers based on the PowerPC processor. It allows applications to share their programming code through special files known as shared libraries. In addition to being able to share programming code, applications which are programmed to use shared libraries can reduce their memory requirements. In response to the success of the PowerPC version of CFM, Apple introduced a version of CFM for Macintosh computers based on the 680x0 processor. This version of CFM for 680x0-based Macintosh computers is the CFM-68K Runtime Enabler extension. What applications are affected by this bug? Only applications which have been explicitly programmed to use the CFM-68K Runtime Enabler can be affected by this bug. Apple Computer products which rely on CFM-68K Runtime Enabler are: OpenDoc, Cyberdog, LaserWriter (versions 8.4 and 8.4.1 only), and the Apple Media Tool. Only the 68K versions of these software packages are affected. This bug does not affect PowerPC versions of these products. There are currently few applications which rely on the CFM-68K Runtime Enabler and therefore Apple does not believe that this problem is very widespread. You can identify applications which rely on the CFM-68K Runtime Enabler extension once the extension is disabled (see below for instructions on disabling the extension). When the CFM-68K Runtime Enabler is disabled, applications which rely on it will report the following error when you attempt to launch them: "This application requires installation of the 'CFM-68K Runtime Enabler'." Is this bug caused by these applications? Not directly. The bug is caused by the use of CFM-68K Runtime Enabler in ways it was not designed to handle. Unfortunately, its limitations were not recognized by the applications. What should I do if I have installed one of these affected products? You should upgrade to the version 4.0 of the CFM-68K Runtime Enabler. If you have a PowerPC-based Macintosh or Mac OS-compatible computer, your computer is not affected by this problem and you do not need CFM-68K. Should I contact third-party application developers about this problem? No. Since a fix for this problem will be accomplished by updating Apple's CFM-68K Runtime Enabler, third-party application developers will not need to assist you with this problem. I have a PowerPC-based computer. Does this affect me? No. The bug is only in the CFM-68K Runtime Enabler extension, which runs only on Macintosh computers based on the 680x0 processor. The Mac OS on PowerPC computers does have code fragment capabilities, but it is accomplished through different programming techniques not affected by this bug. How can I get the technical details about this bug? Apple Technote 1084 has detailed information. For more information on the CFM-68K Runtime Enabler, please see the following Tech Info Library article: Article 21126: " PCFM-68K Runtime Enabler 4.0: Final Version Read Me " The following Tech Info Library article can help you find the Tech Note mentioned here: Article 24493: " Apple Tech Notes: What They Are, Where To Find Them " These articles can help you locate the software update mentioned here: |
| Document Information | |
| Product Area: | Mac OS System Software |
| Category: | General OS |
| Sub Category: | General Topics |
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