On Apr 6, 2009, at 11:44 AM, PETE wrote:
> My G3 iMac and B&W both have the 120GB limit, and I just partitioned > the drives so that both partitions were less than 100GB. Why all the > concern of getting the 128GB so exact? Because the firmware in the QS 2001 and earlier models do not support accessing beyond 131,072 MB, which happens to be 128 GB. These models, which certainly includes all G3s, and most early G4s, have a limitation which is inherent in the firmware, but it is not an absolute contraindication. The method for addressing beyond 131,072 MB is compatible with that method for addressing 131,072 MB and below: 1) addressing up to 131,072 MB requires one command data buffer, which supports 24 bit addressing, and 2) addressing beyond 131,072 MB requires two command data buffers, each of which supports 24 bit addressing, for a total of 48 bits. The large drives all know about the two CDBs, and are prepared to accept them. If the drives only receive the first CDB, then only the first 131,072 MB will be accessed. If the drives receive both CDBs, then the entire drive will be accessed. Modifying the affected model to support two CDBs can be done in two ways: 1) by installing the "High Cap kext" (MacOS 10.4.11 and below, including G3s), and 2) by installing the LBA48 property patches to the firmware (MacOS X, 10.3, 10.4 and 10.5, including most G4s, but not including G3s). After either of the above has been installed, the entire capacity of the drive may be accessed as a single partition. However, it is still safer to install a partition break at precisely 131,072 MB just in case the "High Cap kext" or the LBA48 property patch has been dropped by mistake. With a partition break at precisely 131,072 MB, that portion of the drive may always be accessed. And, should the remaining portion be observed to be missing, remedial tasks may be executed to correct the problem. http://groups.google.com/group/hq-a <+> A home for the Hackintosh community. To subscribe to the HQ-A group, send email to hq-a +subscr...@googlegroups.com --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed Low End Mac's G3-5 List, a group for those using G3, G4, and G5 desktop Macs - with a particular focus on Power Macs. The list FAQ is at http://lowendmac.com/lists/g-list.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to g3-5-list@googlegroups.com To unsubscribe from this group, send email to g3-5-list-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/g3-5-list?hl=en Low End Mac RSS feed at feed://lowendmac.com/feed.xml -~----------~----~----~----~------~----~------~--~---
