On Jan 13, 4:41 pm, Len Gerstel <lgers...@gmail.com> wrote:
> Beiges have onboard 50 pin SCSI. Just get one of the SCA to 50 pin adapters > and plug into the fully supported onboard scsi on the beige. These adapters > are available on ebay for under $5 shipped. I am sure you can easily beat > this on the swap list. This adapters are just wiring/plug adapters with no > (IIRC) electronic conversions. So they all should work with no compatibility > problems. > > I ran many sca drives in my beiges with those adapters with never any > problems. Those cheap adapter do not have any provision for termination, so it may have worked for you, but your SCSI chain was not properly configured, unless you put some other device at the end of the cable to provide termination. I agree with everything else you wrote. Also, when using a SCA to 50 pin adapter, the upper 8 bits (18 unused wires) of the wide SCA drive will not be terminated, and while it is rare, this can cause issues too. SCSI voodoo doesn't happen because it fails to work when people configure SCSI properly. SCSI voodoo happens because SCSI often still works even when it is misconfigured, and then when it stops working, folks act puzzled and call it voodoo. If you want this to be properly configured on a 50 pin bus, get SCA to 50 pin adapters which not only have provisions for termination, but which can terminate the upper byte separately from the lower byte. Then terminate the upper byte on all the drives along the chain, except the one at the end of the cable. For that one, set termination for the entire bus. For properly configured SCSI on a 68 pin bus, you can use the cheap, no termination, adapters as long as you provide termination at the end of the SCSI cable in some other fashion. LVD/SE termination blocks for 68 pin cable are commonly available. The only SCA adapters I've seen which actually have a provision for termination are $20+ (Ebay). They should be cheaper, but they're not. There's one on Amazon which has "termination" in the item title, but the photo shows no circuitry on the board which could be providing termination. Jeff Walther -- 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
