Installing OS X on Legacy Macs - Some Tips

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A Few Words of Introduction and Excuse Making

Considering that the Sliced Apple site mainly involves legacy hardware and use of OS X on that legacy hardware I thought an actual page about installing OS X on such hardware might be…well…nice...but....considering the excellent information already present on other sites, especially the BIG DADDY XPostFacto site, there is really no reason for me to repeat it all here.  Instead I will just provide the relevant links


Although by 2025 not all this information is still as readily available as links or otherwise. I have some more detailed notes I kept from my initial experience. If anyone needs them please ask. And...


I have also mirrored the key software for legacy installs (at least the versions I have retained) on the downloads page. The instructions included with XPostFacto should fill in any gaps.

Mostly this site serves to provide details related to my own experience and hopes to be entertaining as well as help a few others solve some of the more esoteric problems they might encounter and, with that in mind, this page tries to offer an overview of the general process for installing OS X on legacy hardware along with some tips based on my experience.  Due to the nature of my legacy systems these tips will be most relevant on older 1st generation PCI Power Macintosh systems, like the Power Center and Umax clones, and the 7200-9600 Apple systems.

 

The following comments and tips are not an ordered list of steps for installing OS X. It is assumed that anybody trying this knows the basics of how to install an OS. Instead this is a VERY DENSE collection of tips, warnings, advice, and brief how-tos for installing OS X on a legacy machine. I suggest you quickly read (skim) through this guide completely before starting any install to know what it contains so you can refer back if you need to, and to quickly make sure your system is ready, reasonable, and without gotchas. Then just follow the instructions included with XPosfFacto and have fun. 

Experiment, play, and don't take my word for it, or whats the point!!

This information likely contains some errors, and also reflects my experience as others have certainly used some different approaches.

A Special Rev A Power Macintosh "Beige" G3 Warning

 

Rev A PowerMacintosh G3 systems (the Beige G3) have an IDE controller that basically doesn't work with anything other than its original Hard Drive (some users report better luck). Other drives give constant and predicable drive corruption and boot failure as the result. This problem is BAD, makes running ANY OS almost impossible unless you are still using the original hard drive, and should be avoided unless you just want to struggle. The Rev B and C do much better.

 

If you are going to use a Rev A you basically MUST get a Mac compatible ATA PCI card and use that for ALL DRIVES. It is so worth it. If the motherboard has a built in ATI Rage II video controller it is a Rev A. Basically they match the related Bondi iMacs: Rev A - ATI Rage II, Rev B/C - ATI Rage Pro. (the iMacs do not have the "bad" IDE issue).

 

 

Some Overall Comments

A Few Miscellaneous Pointers, Tips, Comments, Details and Guesses Before the Main Collection of Miscellaneous Pointers, Tips, Com......

 

 

Specific Pointers and Tips for Installing/Using OS X on Legacy Hardware

 

Formatting and Partitioning Notes

 

You need a big enough hard drive for the OS X to install and to run including adequate swap space (minimum free space should be 2 GBs). To run well OS X needs an adequate amount of disk space clear AT ALL TIMES for the virtual memory system to work.  When the space gets tight OS X slows down AND becomes unstable.  The amount of free drive space best keep available is somewhat related to your disk size, but in general I would always try to leave at least 4 GB free.  If your boot drive is very large, like >100 GB I might make this 10. I have read the goal is 20 percent. You also want enough for the install (2-3 GB), the applications (1-?...mabye 4), and your users folder (anything). You are going to have trouble running with less than a 10 GB drive and on a modern computer something more like 30G or greater is easier to manage.

 

SCSI may work better as a boot drive for 1st generation PCI Macs.  The original PCI Macs (7200-9600) had PCI 2.0 slots that can slow ATA drive access down, especially with lots of little read, writes (as in virtual memory).  As a result the SCSI port, especially the internal fast SCSI II buses on machines that had them (higher end) should work much better as boot drives.  It may seem like an ATA 100 or 133 drive should be faster, and it might be in a newer machine, but you do not want virtual memory running from an ATA drive through a PCI 2.0 slot. SCSI is a much more sophisticated drive bus but SCSI drives can be expensive so a good option is too install on the SCSI drive, but copy a number of the applications onto a larger ATA drive. You can put aliases to these apps in the real Applications folder. You can also frequently back up excess files from the Users folder to a second drive. 

 

For example: Bertha boots from a 36GB SCSI drive but stores a number of applications (less used) and has a space for each user on one of the ATA drives. Even on new systems new SCSI is always better than ATA.

 

Using Mac OS X on older machines requires the OS X drive to been formatted with Apple's Drive Setup (part of Mac OS 9) while booted into OS 9 (or Intech's Hard Disk SpeedTools.)  This includes the Beiges.  I would use Mac OS 9.l or 9.2 to format from since they are newer, and you need at least 9.1 for XPostFacto anyway.  

 

This formatting requirement is really easy to forget, especially six months down the road after you have been running OS X for some time with nary a problem.  By then you have forgotten that Mac OS 9 ever darkened your drive casing and end up turning what should be an easy XPostFaco install on your machine, a friends, or a second drive into a several day frustrating waste of time. You know you did everything right but the just system refuses to boot from the new OS X drive until your finally remember that two months ago you reformatted it in something and have been using it as a non boot drive in OS X just fine. Repairs, installs on other drives (that just happened to have already been formatted in OS 9), along with OS X updates, and upgrades all worked just fine running from OS X just like on any other computer and your never think of any OS 9 requirements, but there are two:


1) The boot disk must have been formatted by Mac OS 9. I would use Mac OS 9.l or 9.2 to format from since they are newer, and you need at least 9.1 for XPostFacto anyway.

2) If your PRAM gets reset you need to briefly boot into 9.1/9.2 to reset it for OS X.

 

Installing Mac OS X on a drive attached to an older ATA sporting Macintosh (like the Bieges and early iMacs) requires that the ENTIRE OS X install reside in the first 8 GB of the drive (this is actually much more complicated and numerous hackish work arounds are possible).  As a result the OS X Installer will refuse to run on such drives larger than 8G until they are partitioned allowing the installer to use a partitions that itself lies in the first 8G.  This 8G problem does not effect OS 9, nor does a booted OS X system have trouble seeing the rest of the drive. This problem does not effect SCSI drives.

 

This is actually two separate and opposite problems caused by the same core isssue. The little hardwired device drivers in the early IDE controllers were limited and couldn't actually see more than 8 G of drive, not a problem in a world of 2 and 4 G drives.  OS X uses its own drivers so doesn't care once it is loaded but the Mac firmware has to use the IDE drivers and the Mac firmware has to find and load the OS X bootx file.  To do this the bootx file (always in the first 8 G on OS 9 systems...well OS 9's version)  has to be in that first 8 G (After that the 8 G problem doesn't mattter.) The easiest way to guarrantee this is to require that the entire boot drive (or a partition there of) be in the first 8 G.  This problem does not apply to the SCSI buses.

 

Running from such a puny drive is actually a nuisance and is the first problem (well problem 1.5 at best, figuring out whether the top are bottom partition on a drives setup is the "first" part is is problem 1). Having OS X be useful while having your user folders and system stuck on a little 8 G drive is a pain.  Tricks to distribute stuff over several drives is a pain.  Being limited to using only 120 G hard drives is a pain when you can get 200 G drives for $50.  It is often better just to get a (Mac supporting!) ATA PCI card (like the SIIG or Sonnet ATA 133 PCI cards) that can see the entirety of any modern drive (like 500 G monsters).  Using a "helper" disk (part of XPostFacto magic) as the intial boot drive to get that bootx file works and at least after installation (which still refuses) you "run" from the "Big" partition.

 

The second problem is that OS X installer does not distinguish between older on-board IDE buses that have this limit and new ATA PCI cards that don't.  A newer ATA 66, 100, or 133 card can see an entire attached drive just fine. But if the installer sees an ATA drive on an older Mac it assumes it is on the the on-board bus and demands the first 8 G only. This leads many users to believe they must adhere to that limit even on new cards and drives when they don't have to. This is an install problem, not a run problem. The problem is how to get the install onto the full drive that can be used (connected via a card) when the installer is refusing.

 

There a several ways around this second install only problem: 1) Break out a little 8 G (or less) partition  (you need a bail out install anyway), install onto the little partion, then use of one of of the cloning tools to copy the install to the big partion, or 2) temporally install the ATA drive in a newer system and use that system to install OS X, then put it back in the older one, and 3) XPostFacto 4 (now at beta) is trying to trick the installer into not having that limit, and my favorite 4) just use the installer anyway, but bypass the stupid check.

 

Locating and Running the OS X Installers Manually

 

The Install CD or DVD gives the impression that you must boot from it for the installers it contains to work.  This is not at all true.  The only requirement is that the installers must be run from OS X since they use the OS X installer application so if you can boot at all in X you can run the installers manually.  It is quite easy to do a full OS X install on some second drive using the install CD as just another data CD while you also check your email, surf, author rants, play in the terminal, and download porn. Just going one step past the Install CD's Initial screen avoids the 8 G check but does allow a normal full install. Unfortunately this is not really an option for the very first attempt to put OS X on some legacy machine since you aren't running in OS X in the first place.

 
How to Access the Installers Manually

 

To run the installers manually just double click an individual installer package (.pkg files) or the virtual collections called .mpkg.  The installer packages are located in the Install CD's OS X System folder. To find it look for the packages in /System/Installation/Packages/


When you insert the Install CD or DVD the window that opens automatically is NOT the root window, so close it and double click the CD or DVD icon.


The Install DVDs shipping as part of systems go a step further and make their System folders invisible which can be very confusing.  There are a number of work arounds such as:  Tell the Finder to show invisible files via its hidden preference, or Use the Terminal to open the invisible folder in the Finder, etc.

 

To use the Finder to see invisible files either get TinkerTool, or go to my download page and grab Toggle Finder Invisibles, or
open the Terminal and just type:  

 

defaults write com.apple.Finder AppleShowAllFiles -bool yes

 

reverse it with: 

 

defaults write com.apple.Finder AppleShowAllFiles -bool no

And you thought the Terminal was useless!

 

The Finder will take a bit to realize you snuck in a change to a preference and I am impatient so I restart the Finder by force quitting it.


For me I usually just use the Terminal to go straight to the DVDs system folder and open it directly in the Finder using:

 
     open "/Volumes/whatever your DVD is called/System"  
 
for example:  open "/Volumes/PowerBook G4 Install DVD/System"

 

 

Video Card and Quartz Extreme Notes

 

Get a better video card to replace the built-in video. Newer video cards do much better running OS X, many PCI Video cards will handle Quatrz Extreme (QE), and you can still use the built in video for a second monitor.  Note that PC video cards and Mac video cards are DIFFERENT and you must have one with firmware that supports the Macintosh. PC Video cards DO NOT WORK unless they converted (not possible on most) to Mac cards by flashing their firmware. I don’t know about the newest nVidia stuff since they were talking about making all their cards dual supporting.

 

The only card "officially" available for PCI Macs that can run QE  (or that is easy to find) is the ATI 9200 PCI Mac Edition (128M).  This card came out in late 2004 and replaced the prior lone offering, the ATI 7000 PCI Mac Edition (32M).  The ATI 9200  Isells for around $130 but if you can find a used or unneeded ATI 7000 it works just as well for less money (the 1st and 2nd generation machines can't use the full potential of the 7000, much less the 9200).  They are easy to find on eBay and for awhile there was a small cottage industry of people flashing the much cheaper PC Editions to Mac Editions and selling them.

 

If you want to do it really cheap and like doing hardware mods you can get a PC PCI video card (usually done using an ATI or ATI Powered PCI 7000 ), change out the flash ROM to 64k from 28k (if needed), and flash it using the Mac firmware to a Mac ATI PCI card.  You can probably do the whole thing (no damaged cards though) for less than $50.  Lots of instructions exist for how to do this.  Bertha uses a flashed PC card, a Power Color Radeon 7000. The Beige and Power Center both use "official" Mac Edition ATI 7000s.

  

Give PCI Extreme a try. Staring with 10.3 Apple offloaded some of the Quartz processing (GUI eye candy) to the graphics processors found on all new macs. Officially Quartz Extreme (as it is called) requires an ATI Radeon (or equivalent nVideo) AGP graphics card but technically it runs on PCI cards as well (the Radeon requirement is real). The benefit of enabling QE on legacy PCI Mac with suitable video cards is a subject of debate in the Mac universe, but many people think it helps a lot, me included, and there is little harm in checking it out since it seems clear that certain systems do get real benefit.  

 

It is likely that your system will see such benefit if it is a higher end (Professional) 1st generation PCI machine (like a 7500-9600's) that has the older PCI 2.0 slots and is suitable upgraded with adequate memory and a decently fast CPU card.  Minimally upgraded older machines, especially the lower end one with the slowest of memory have less benefit since they can barely do their part of the QE dance so the card can do its part.  Newer machines (pre AGP) with faster motherboards and the newer PCI 2.1 slots may also see less benefit since QE might pull so much data it starves out the other components .

  

The controversy concerns the impact on available “bandwidth”. Bandwidth is a term for how much information a system can move at any one time, or how big its data pipes (highways, conduits, pathways) are. The term is often used to refer to the downloads speeds of someones internet access.  Cable modems are said to have “more bandwidth” than regular phone modems and are called “broadband”.  The same term is used to describe a motherboards ability to pass data between memory, the CPU, cards, ect…  QE requires a ton of information to be constantly supplied to the video card and theoretically this could tie up all the bandwidth on the motherboard such that needs like accessing the hard drive get choked out. This could cause the system to slow down. Most users (from what I can tell) think that in real use activating QE helps and don’t see much real world slow down.  It generally looks as if those who insist on a slowdown seem to say ‘we don’t care what you think you see in real use, we insist QE must make it worse.’ Check it our for yourself and remember, You are using the system so what works for you IS what works.  For more on my views sess my discussion on why PCI Quartz Extreme just might work better than some might guess.

 

Get PCI Extreme here (or my downloads page) or search version tracker. Make sure you use the correct version for your system and note that you will need to re-run it after each system update. If you like QE skip 10.3.7, use the newer update.

  

Activating the Caches on CPU Upgrade Cards

 

Activate your CPU upgrade card’s cache or your machine will be dog slow. Most CPU upgrades cards require YOU to do something (in OS 9 and before, and OS X) to activate their caches, and they don’t work well with the caches off.

 

The cache is a special pool of memory connected to the CPU that can be accessed faster than main memory. Caches are what allow a computer to run a CPU that is much faster than the computer’s motherboard and get benefit (i.e. an iBook with a 1Ghz CPU but an 133Mhz motherboard). This is even more important for older systems with a fast upgrade,. So if the computer seems REALLY slow, be sure that cache is on. (Bertha has a 1Ghz G4 CPU, but only a 50 Mhz bus, and even slower memory so if the cache is OFF it is SLOWW)

 

There are several ways to activate the CPU upgrades cards caches:

Other Tips, Suggestions, and Warnings

 

If you are using a first generation PCI system that has a Cache DIMM in its L2 cache slot pull it out.  This L2 cache is not anyting like the ones on the CPU cards, doesn't help if your are using a CPU upgeade, and might hurt.  Drill a hole in it and hang it from you rear view mirror.

 

10.0 and 10.1 were slow on SUPPORTED hardware so certainly skip them on older hardware. 10.0/10.1 are real dogs speed wise, but if you want to count "bounce marks" (the number of Dock bounces it takes to launch an application) then go for it.  On my current PowerBook system Internet Explorer (not the worlds fatest app and never used) takes 4 bounces first launch and 1 after that.  I remember in 10.0 it was more like 30 bounces.  I wasn't sure if OS X was launching it or just trying to shake it awake.  I had time to bake a cake. 


In reality 10.0 and 10.1 were just a continuation of the public beta and largely feature incomplete. Go to at least 10.2, its faster on all hardware but the increase is even more pronounced on older stuff.

 

Use the most recent OS version (major) you can get.  From 10.0 through 10.4 (at least) each major OS upgrade was faster on ALL hardware, but even more noticeable on legacy hardware, than its predecessor. This means your legacy machine is getting faster, not slower over time.  Do not install anything older than 10.2 but 10.3 was REALLY significantly faster than 10.3, especially on G3 based systems. 10.4 appears faster than 10.3 in early testing.

Get as much memory (RAM) as possible. Legacy machines have slow buses and often slow drives so they are more sensitive than newer machines to slowdowns from having too little memory.  384 MBytes of RAM can work just fine in something like your old iBook running 10.2, but is slow and unstable on a legacy system. Just a change to 512 M makes the system stable.

I would max the memory possible for your system, but my functional recommendations are:

 

  1. Mac OS 10.2 Jaguar 384 M Minimum (256 is very painful) 512 M is works well
  2. Mac OS 10.3 Panther 512 M Minimum , 768 works well
  3. Mac OS 10.4 Tiger – I have not installed this on a legacy machine yet. I am still testing some Panther requiring issues so Bertha is hangin’ back.

 

CPU upgrade cards ROCK!! (but are expensive) and work great with OS X.  A G3 or G4 CPU used to be required for 10.2 or 10.3 but now it seems that 10.2 is working on some older CPU's like the 603's. There is no way I would waste my time (unless for pure folley) installing any OS X version on a pre-G3 running system.  I would not want to  use a system for anything but Unix serving (such as a web/print/file server) and not GUI stuff without at least a 400 Mhz G3/G4 card with a 512K or 1M cache, at least 512 MBs of RAM, a decent 10 G Hard drive (at minimum) running from whatever the preferred bus is (SCSI on the Beiges and earlier, ATA after that), and a newer PCI video card probalby running QE, and if I had a choice would go straight to 10.3.  It has a number of additional features, looks better, is required for QE, and is noticeable faster than 10.2 or any system, even more so on older CPU's.

 

Running OS X from a decently new SCSI drive on the original bus is often faster than a newer ATA drive attached via a PCI ATA card. SCSI can read and write at the same time and has other optimizations that seem to help these older Macs compared with the ATA CPU overhead. Test it and see what works for you. Believe how it feels in use and NOT benchmarks, especially with drives, especially comparing SCSI to ATA.

 

Install OS X without any upgrade PCI cards installed that you can manage to temporarily remove. OS X is much more tolerant of extra hardware than OS 9 and that can make installation tricky since OS 9 is probably going to be used for a bit.  After you get OS X up, and upgraded to the latest version, shutdown, re-install those cards, and then startup again. The systems will start straight into OS X after a shutdown or on reboot just like any other system running OS X. If you are having problems, install those cards ONE at a time.

  

Interval OS X system updates rarely have any issues (i.e. 10.2.3 to 10.2.4 or 10.3.3 to 10.3.4) unique or exclusive to legacy systems and can be installed via the normal built-in software update mechanism. If you want to check first (always a good practice) look on the XPostFacto forums. The only one I am aware off unique to legacy machines was 10.3.7.  That update broke PCI Extreme.  It returned in 10.3.8.

 

If at any point you can’t boot into OS X, or you told the system to boot from a different OS X drive and its not working, or your PRAM settings have been cleared/munged GET BACK TO OS 9. With a few new exceptions as XpostFacto adds support for recently orphaned hardware (like the beige’s) pre OS X systems do not know how to find the boot file for OS X systems so something must set it in their firmware. If your system has forgotten this, or it is not working you have to get back to OS 9 to reset it. Don’t waste your time trying to force it into X, the system doesn’t know how to do it.

 

If your old Power Mac is one of the one that supports memory interleaving, then By God interleave that memory.

 

After all is working turn off the setting to always start verbose if you ever turned it on.  Verbose is helpful for troubleshooting but seems to slow things down a bit.  You can always invoke verbose on any single start by holding command-v at first start (ADB keyboard...do you need it?)

 

Unless you are using a PowerMacintosh G3 or newer (the Beige's) avoid like Death, Taxes, and Gonorrhea ANY aftermarket Ethernet card that uses the RealTek8139 chipset (like the D-Link 530 tx+). It is a cheap chipset and is present in lots of cards, including many combo cards. It does not work well with legacy Macs equipped with 2.0 PCI slots and you do not want networking problems if using OS X. The problems this chipset causes causes are often intermittent, severe, and difficult to isolate to networking.

Your onboard Ethernet should work fine and it is PLENTY fast for ANY internet connection.  If you need a better LAN connection I suggest something like the Asante 696 as that works great for me. The Motorola Wireless G PCI card also works great (OS X thinks it is an normal Apple Airport Extreme card).

 

USB2.0 doesn’t work very well on many older machines especiallly those with PCI 2.0 slots (7200-9600 and clones) and can cause lots of problems, like freezing. Just be happy with USB 1.1.  Use FireWire for higher bandwidth needs (be careful which PCI card you choose).

Put a recent copy of XPostFacto for both OS 9 and OS X on ANY DRIVE you might ever boot from.

 

Put a minimal bootable copy of OS 9.1 on every permanently attached drive unless you would prefer spend 10 hours trying to get booted again rather than use the 20 MByes of drive space.

 

Either using a two or more partitions on your only drive, or a second internal drive, put a minimal bootalbe (XPostFacto modified) OS X install to act as a repair and bail out drive. You can have OS 9 AND OS X on the same drive.  Lots of utilities and bail out options only work from OS X and you can run any or all of the installers manually directly from the install CD IF your are booted into OS X from something.  SEE MY BAIL OUT ALGORITHM.

 

Keep a copy of the latest OS X Combo (COMBO!!!) system updater on any drive that also has an working OS X install on it. The combination updaters replace a large percentage of the core system and just running them often fixes any problems. They can, of course, be run on the drive you are booted from and they are nice to have ready so you don't have to download a 100 M file.

 

If your don't have built-in USB and are using a aftermarket PCI USB card then install the OS 9 USB PCI card support into any any OS 9 System you might EVER boot from.  Without those drivers OS 9 will not see your USB ports, including a USB mouse and keyboard.  It really sucks to use XPostFacto to boot back into OS 9, get all the way started, then realize your attached USB mouse and keyboard don't work, THEN remember your ADB keyboard and/or mouse is broken or missing.  Even if you have them close bye they won't work until you plug them in and start again. If you don't have them YOU CAN'T EVEN RUN XPOSTFACTO TO GET BACK TO X where everything works just fine. If you just install the darned drivers for PCI cards your USB stuff will work in OS 9 and X and your will forget such a nightmare is even possible.  Do it now or you will forget!  It may be years before you see OS 9 again and need that ADB keyboard. Bluetooth has zero OS 9 support so if your are Bluetooth dependent for keyboards and/or mice just install the USB drivers and keep USB stuff around.

 

If you are stuck, nothing works, and you despair some horrible hardware calamity has claimed your motherboard...RELAX..clearing the firmware/resetting the PRAM either by holding command-option-p-r on start (and actually having pressed tmem before hitting power) and sometimes even pulling the PRAM battery and waiting for several days, or using your cuda switch (motherboard reset) often magically revives the motherboard. (or it may be dead). Motherboard resets often have fits starting back in OS 9 so remove non-critical hardware and put it back later.

 

  

  



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