> TMI-Sometimes booting 2nd HDs can be problematic on Beige, there is > one ROM version (A) that doesn't support any slave drive booting, > although XPF can boot slave drives on normally early Beige with ROM A > by using a bootable master HD as an XPF Helper Drive. Later ROM B & C > can boot both master & slave. You can place newer B & C ROMs into > older Beige. It's a little complicated because there were three ROMs > (A, B, & C) and three hardware revisions of Beige (1, 2, & 3) and the > ROMs mostly matched up with the models revisions, but if you really > wanted the fastest possible Beige you probably wanted an early Rev.1 > model that had an overclockable System bus which was determined by the > "Grackle" chip (blue colored chip on motherboard). Most Rev.1's had > Grackle chips capable of overclocking from 66MHz System Bus to 83MHz, > but the Rev.2&3 had slower Grackle chips that were not capable of > overclocking. The fastest possible Beige would be a Rev.1 Beige w/fast > Grackle with a version B or C ROM chip so you could boot all internal > devices and overclock the System bus to 83MHz.
Normal builds were Rev. 1A (Rev. 1 mobo and Rev. A ROM), Rev. 2B (Rev. 2 mobo and Rev. B ROM) and Rev. 3C (Rev. 3 mobo and Rev. C ROM). B and C ROMs provide essentially the same functionality (mainly support for slave IDE drives). Rev. C ROMs corrected a bug in the video support which was present in Rev. A and C ROMs. The fastest and best configuration would be Rev. 1C. Occasionally, Apple would respond to a customer complaint for lack of slave support on Rev. 1A machines, which were usually 266 MHz examples, by supplying a Rev. B ROM on an exchange basis. Machines with Rev. A ROMs which also have a factory Zip drive will have a SCSI Zip, which is why the Beige PSUs have BOTH a standard Molex and a miniature Molex power connector. The SCSI Zips required the miniature connector; the IDE Zips required the standard connector. The early Beiges were really a "perfect storm": Apple initially couldn't figure out how to properly support slave drives, and Iomega initially couldn't figure out how to make its Zip drives work as slaves. So, there was some overlap between the availability of slave support from Apple, and the necessity for SCSI Zips. Even after slave support was available from Apple, Apple only provided master cables for the hard drive bus. At one point some years ago, my company manufactured combo master and slave hard drive bus cables. Quite a number were sold. The solutions for Mini Tower, Desktop and All-in-One combo master/slave hard drive cables were quite different. Every one of my cables were tested and passed at UATA/33 (33 MB/sec), even though the Beige IDE buses were limited to 16.67 MB/sec by the host adapter chip. -- -- You received this message because you are a member of G-Group, 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 For more options, visit this group at http://groups.google.com/group/g3-5-list --- You received this message because you are subscribed to the Google Groups "G-Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to g3-5-list+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
