On Jun 17, 10:15 am, insightinmind <billycarm...@verizon.net> wrote: > Someone stated (Peter, I believe, if I understood correctly) Apple, > historically, uses an HP/Compaq patented Startup protocol that > requires the "Cable Select" (slitted) off the mobo ATA cable at > Startup, then, depending on the machine and particular hard drive > specs, uses whatever the drive is set to (CS/Single/Master/Slave).
First the caveat that I am only familiar ... to whatever extent I have an understanding ... with the hard drive side of this discussion. I haven't worked with PATA drives in a Mac and I certainly have *never* worked with a PPC Mac (though I *have* worked on PPC systems so the PPC is not a complete mystery to me ;-). What confuses me in the above is the speculation that the hardware might somehow "require" Cable Select. Support for Cable Select is mostly about the cable you use. The hardware/controller has a relatively small part to play. I'm basing that on what I read in this Wikipedia article which sounds credible to me. http://en.wikipedia.org/wiki/AT_Attachment#Cable_select In particular ... "Cable select is controlled by pin 28. The host adapter grounds this pin; if a device sees that the pin is grounded, it becomes the master device; if it sees that pin 28 is open, the device becomes the slave device." and "Pin 28 is only used to let the drives know their position on the cable; it is not used by the host when communicating with the drives." To that I'd add that I can't see any way in which a controller could "interegate" pin 28 to learn anything about the attached drives. So I don't see how the hardware could "require" Cable Select in any way. Bottom line as I see it, there are three reasons why Cable Select might not work: 1) The drive doesn't support it (correctly). 2) The cable doesn't implement it correctly. (Most likely scenario and easiest to test for/fix IMO. PATA cables are one big PITA IMHO :) 3) The controller doesn't properly ground Pin 28. (Can't say how likely or not this might be. Depends on the "age" of the hardware, I suppose.) But, then again, I've been wrong before ... -irrational john --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
