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Installing OS X on a WallStreet Using an External CD-ROM

Charles Moore - 2006.03.01 - Tip Jar

Booting OS X from an External SCSI Drive

From Jeffrey Kafer


I can't be entirely certain, since I've fiddled with so many different configurations, but I believe that I have successfully booted from external SCSI devices with Old World machines under OS X. My trusty CD300 CD-ROM drive (that uses CDs in caddies) has been indispensable for installations and upgrades, and [it's case] also has served as a temporary home for SCSI hard drives on many occasions.

With regard to the 8 GB partition rule, I thought that only applied to IDE drives, not SCSI devices. I am almost positive that the SCSI drive in my 7300 is larger than 9 GB and boots into OS X 10.2 without partitioning.


Hi Jeffrey,

Thanks for the report.

Booting from external FireWire drives is certainly possible. I do it all the time. My only nominally OS X supported Old World Mac is a WallStreet PowerBook, but it won't even boot from a Jaguar install CD.

Since an internal SCSI drive just connects to the SCSI bus, external or internal should not be an issue, one would think.


Editor's note: The 8 GB restriction applies specifically to IDE/parallel ATA hard drives. dk

Installing OS X on a WallStreet Using an External CD-ROM

From Geoffrey Peters

I read Mat's letter to you (see Can WallStreet Boot into OS X from a SCSI CD Drive?), and I can offer something of a solution and a bit of relevant information for you & your readers. Apologies for the length, but the details are important.

Mat, it sounds as if the centre-frame chassis is warped, or at the very least has been reinstalled incorrectly. It's an incredibly fiddly piece to get "just so"; failure to do so means the battery won't latch properly and/or the optical drive pod won't seat properly. As for the PC Card cage - warping, or one of the retaining catches is broken. The entire cage will need replacing - check eBay, a surprising number of loose PowerBook parts always seem to be available.

As for your desire to get OS X onto it, yes, it can be done. But you're going to have to rely on your WallStreet's internal hard drive, and you're going to need an appropriate universal Mac OS 9.1 Installer CD, as well as your external CD drive. As you want to run 10.3.9 (a wise choice, in my opinion), you should use the last build of XPostFacto 3, not 4 - newer does not always equate to better. You should also make sure that the OS X 10.3 discs you have are suitably "universal" enough; by this, I mean that they should be 10.3 - no greater than 10.3.2 - and a true install set, and not an Update set.

If you chose to work from backups instead of risking your precious OS X masters, be careful as to what kinds of media they are burnt to. Many older CD drives - and essentially all of Apple's SCSI drives up to and including the 24x speed - cannot read CD-Rs that use p-cyanide (the common light green or almost-silver yellow-green ones), which is unfortunately most of them. You will need to make new copies using blue-dye Verbatim AZO CD-Rs or find some old "gold" 2x or 4x speed CD-Rs.

Firstly, ascertain that the SCSI CD drive is correctly configured and is a model that is recognised as a bootable device by the Mac. Then insert the 9.1 CD into the drive, restart the Mac, and press the C key until you see the blue smiley Mac face. You should hear the CD seek, and eventually be presented with the cream-and-disc desktop pattern that says you've booted from the CD successfully.

If the Mac ignores the CD entirely and either tries to boot from the Mac's internal hard drive or gives you the dread "blinking drive folder", then either the SCSI device is not set up correctly, there is a cabling problem, or the drive is a mechanism that the WallStreet cannot recognise without a driver.

If your SCSI CD drive is a "pull" from another Mac, then you either have a cable problem or a termination problem. If you have access to another Mac with SCSI - preferably not another laptop - test it there. If it works, then the CD drive is over-terminated. Most Apple laptops do not provide the TRMPWR voltage, so there's nothing to power the passive terminators that are either jumpered to "Terminator Enabled" on the drive mechanism itself, or the common passive terminator block on the back of the case.

Check for both and remove both, then try the above test again. If it fails again, check the quality of your SCSI cabling, starting with the IDC cable run inside your external SCSI case. If you are using the official Apple HDI-30 to 50-way Amphenol cable, you aren't terminated, and the internal SCSI cable appears fine, odds are the CD mechanism itself is the problem. If you are using a HDI-30 adaptor and a normal 25-to-50 cable, it could be the adaptor - in my experience, they're not very robust - often individual pins will sneak back into the adaptor's housing. If the main SCSI cable you're using is thin - that is, flexible enough to easily tie a basic bow-knot in it - discard it and find a stiff, thick one. Those thin SCSI cables are an abomination, and I cut and discard every one I encounter.

Yes, this is fiddly. Douglas Adams once said, "Getting SCSI right is one part know-how, one part experience, one part luck, and three parts voodoo." Clever man, was our Doug.

Once you have an external CD, you can boot your WallStreet into Mac OS 9, and we can continue.

Copy XPostFacto, uncompressed, to a CD-R and copy it to the top level of the WallStreet's hard drive. Boot from the OS 9 CD, then drag everything but the XPostFacto folder to the Trash and empty it. [Editor's note: You did back up all your important files, didn't you?] Install a fresh version of OS 9 from the CD - ensure you check "Update hard disk drivers" - and leave everything else as default; do not customise what gets installed and what does not.

Once complete, go to the Startup Disk control panel and ensure the WallStreet's hard drive is the startup device. Restart.

If the Apple CD/DVD ROM driver extension in OS 9 can't see it, neither will the patched OS X installer.

Once you have the desktop back, insert OS X Install Disc 1. If it fails to mount on the desktop, either your media is bad (try the originals if you're working from backups), or you're using a CD mechanism that OS 9 doesn't recognise. If this happens, give up now and find a different CD-ROM mechanism, preferably one from an old SCSI Mac. If the Apple CD/DVD ROM driver extension in OS 9 can't see it, neither will the patched OS X installer.

Insert OS X Install Disc 1 and wait for it to mount to the desktop. Now you can launch the XPostFacto app. Choose the Install CD as your install source, and the hard drive as the destination, and let 'er rip.

XPostFacto will write its little bootx and modified microkernel to your hard drive and then restart. When it does, you will hear a tiny amount of activity from the hard drive as the bootx is loaded from it - it, in turn, boots the disc in your external CD drive and loads OS X and then the Installer. You should now be able to complete the installation normally, and once done, restart into OS X from the hard drive.


Hi Geoffrey,

Thanks do much for this detailed tutorial.


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Charles Moore has been a freelance journalist since 1987 and began writing for Mac websites in May 1998. His The Road Warrior column was a regular feature on MacOpinion, he is news editor at and a columnist at If you find his articles helpful, please consider making a donation to his tip jar.

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