No, it appears to have been one of the first models to use an IDE hard disk, but the CD-ROM was still SCSI. At any rate it has a SCSI bus.
- Jonathan Morton On 23 Jan 2014 01:40, "J.S. Garrison" <[email protected]> wrote: > From memory, doesn't the 637 use an IDE hard disk AND CD ROM? > > > Jeff Garrison > ------------------------------ > *From:* Jonathan Morton <[email protected]> > *To:* [email protected] > *Sent:* Wednesday, January 22, 2014 1:55 PM > *Subject:* Re: Performa 637 CD-ROM replacement > > > On 22 Jan, 2014, at 11:34 pm, Lee Kolb wrote: > > > 1,2,4, parity, sector size, terminator, and term. power. > > I'm puzzled by the first three, because I thought the max. no of SCSI > devices was 6 > > "Narrow SCSI" as found in old Macs can have device IDs from 0-7, where 7 > is 1+2+4, a standard 3-bit binary code. ID 7 is usually reserved for the > controller, which is just a device on the bus which happens to be the Mac > itself. So there can be 7 "slave" devices (0-6) plus the controller. > > The internal CD-ROM in a Mac is usually ID 3, so since this is a > replacement for that, set jumpers 1 and 2, and leave 4 open. You'll also > need to set the Parity jumper, to ensure that an odd number of ID jumpers > are set in total. > > > and I have no idea how the other four should be set > > Each physical end of the SCSI bus should be terminated to prevent > reflections of signals from causing interference. However, this is one of > the black arts of SCSI. If in doubt, look more closely at how the old > drive was jumpered, and assume that any features that are new on the > replacement drive should be left unselected. > > If the CD-ROM is on the *last* connector of the cable and there *isn't* an > external terminator at that point (you'll be able to see it easily), then > set the terminator jumper. > > If the CD-ROM is on the *last* connector and there *is* an external > terminator, set the "terminator power" jumper instead. That'll allow the > external terminator to work. > > If the internal hard disk is on the last connector, so that the CD-ROM is > *not* physically the last device, then leave both the terminator jumpers > open. There should *not* be an external terminator at that connector. > > Sector size should be left open to give 2048-byte sectors as is usual for > CD-ROMs. When jumpered it would have 512-byte sectors to emulate a hard > disk. Apparently some UNIX workstations needed that to boot from it, but > it's irrelevant to a Mac. > > - Jonathan Morton > > > -- > -- > ----- > You received this message because you are a member of the Vintage Macs > group. > The list FAQ is at http://lowendmac.com/lists/vintagemacs.shtml and our > netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml > To post to this group, send email to [email protected] > To leave this group, send email to vintage-macs+ > [email protected] > For more options, visit this group at > http://groups.google.com/group/vintage-macs > > Support for older Macs: http://lowendmac.com/services/ > --- > You received this message because you are subscribed to the Google Groups > "Vintage Macs" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/groups/opt_out. > > > -- > -- > ----- > You received this message because you are a member of the Vintage Macs > group. > The list FAQ is at http://lowendmac.com/lists/vintagemacs.shtml and our > netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml > To post to this group, send email to [email protected] > To leave this group, send email to > [email protected] > For more options, visit this group at > http://groups.google.com/group/vintage-macs > > Support for older Macs: http://lowendmac.com/services/ > --- > You received this message because you are subscribed to the Google Groups > "Vintage Macs" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/groups/opt_out. > -- -- ----- You received this message because you are a member of the Vintage Macs group. The list FAQ is at http://lowendmac.com/lists/vintagemacs.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to [email protected] To leave this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/vintage-macs Support for older Macs: http://lowendmac.com/services/ --- You received this message because you are subscribed to the Google Groups "Vintage Macs" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
