dsb@mbunix.mitre.org (Blodgett) (12/28/90)
Question: I have heard that there is a bug in the Mac ROMs in the fx, ci, and possibly the si. I was told that this bug is called a redundant memory error. Normally the mac moves data 32 bits at a time, but when the computer is pushed to its upper limits of memory that it only moves 2 bits at a time. Has anyone else heard about this ? If so is there a work around, or a bug fix planned? Any information further information would be greatly appreciated. -- | Scott Blodgett | The MITRE Corporation | | (617) 271 - 4960 | D092, Communications Control Engineering | | dsb@mbunix.mitre.org | Burlington Road, M/S F303, Bedford, MA 01730 | +------------------------------------------------------------------------------+
lsr@Apple.com (Larry Rosenstein) (01/10/91)
In article <127472@linus.mitre.org>, dsb@mbunix.mitre.org (Blodgett) writes: > > > Question: I have heard that there is a bug in the Mac ROMs in the > fx, ci, and possibly the si. I was told that this bug is called a > redundant memory error. Normally the mac moves data 32 bits at a time, > but when the computer is pushed to its upper limits of memory that > it only moves 2 bits at a time. The description of the bug is totally wrong (and doesn't even make much sense). The actual bug involves moving memory blocks around when trying to make room for a non-relocatable block. The bug is that a hint telling the Memory Manager where to start scanning the heap is wrong, and the Memory Manager ends up scanning the entire heap unnecessarily. The bug is only supposed to affect applications that allocate a lot of non-relocatable blocks, which means it doesn't show up in the majority of applications. > > Has anyone else heard about this ? If so is there a work around, or > a bug fix planned? There is a fix being worked on. Larry Rosenstein
warner@scubed.com (Ken Warner) (01/10/91)
In article <11678@goofy.Apple.COM> lsr@Apple.com (Larry Rosenstein) writes: >In article <127472@linus.mitre.org>, dsb@mbunix.mitre.org (Blodgett) writes: >> Question: I have heard that there is a bug in the Mac ROMs in the >> fx, ci, [etc] >[etc.] The actual bug involves moving memory blocks around when trying >to make room for a non-relocatable block. The bug is that a hint telling >the Memory Manager where to start scanning the heap is wrong, and the >Memory Manager ends up scanning the entire heap unnecessarily. >The bug is only supposed to affect applications that allocate a lot of >non-relocatable blocks, which means it doesn't show up in the majority of >applications. There is a fix being worked on. Is Smalltalk-80 and/or Objectworks 4.0 such a program that allocates a lot of non-relocatable blocks? Ken Warner
Greg@AppleLink.apple.com (Greg Marriott) (01/11/91)
In article <11678@goofy.Apple.COM> lsr@Apple.com (Larry Rosenstein) writes: > dsb@mbunix.mitre.org (Blodgett) writes: > > Has anyone else heard about this ? If so is there a work around, or > > a bug fix planned? > > There is a fix being worked on. > > Larry Rosenstein This bug is fixed in System 7. The next beta CD will have the fixed version. I want to stress that this bug DOES NOT cause a crash, and only happens in rare cases. Very few applications trigger this bug, and if they do it just slows things down a bit. Greg Marriott Blue Meanie Apple Computer, Inc.