During the late 1990s and early 2000s the Macintosh was getting more powerful, and for a while the PowerPC G-series CPUs provided more computing power than comparable Intel chips. But by the middle of that decade the G5 was reaching an engineering tradeoff in terms of processing power versus thermal output; the fastest Macs ran very hot and required the development of liquid cooling systems. These limitations prevented the release of G5 based PowerBooks (though prototypes were rumored to exist), and required Apple to think differently about its future.
So in 2006 Apple stunned the world (again) by announcing they were going over to the Dark Side: the Macintosh was going to switch to Intel processors. Apple had been secretly compiling Mac OS X for Intel shortly after it’s evolution from NeXTstep. To allow developers to prepare their own software for the change, Apple designed special Macs with Pentium-based motherboards inside PowerMac G5 cases for testing purposes. Called Developer Transition Systems (DTS), these Trojan horse “PowerMacs” came with a special developer version of Mac OS X Tiger 10.4.1 for Intel and were leased, not sold, to developers. The mothership required all DTS units to be returned after one year, so very few of these hybrid Macs survive outside the gates of Cupertino.
The DTS is an interesting beast. A small logic board labelled Barracuda sits inside a ridiculously large tower (to fool the passers-by). The processor is a 3.6GHz Pentium 4 with Hyper-Threading. But despite being an Intel version of Mac OS X Universal applications will not launch in Intel mode, they just bounce a few times in the dock then abort. In order to launch third party software you need to check the preference to “Launch using Rosetta” in the Finder’s Get Info window. As far as these apps are concerned, they’re still running in a PowerPC world.
When you first start the machine a BIOS screen appears, allowing you to hit F4 and set the boot drive order, system date, etc.. No Open Firmware here. Unlike other Macs the hard drive needs to be partitioned using Master Boot Record (MBR), not GUID as used for all shipping Intel-based Macs. That’s unique. This thing is really a PC with proprietary software pasted on top. Look at all those Pentium 4 CPU features!
As a VMM addition, this was a real find. I got system from used Mac shop that keeps an eye out for interesting items; they got it from someone who was going to dispose of the tower as scrap metal. Fortunately that fate was avoided and the DTS arrived in working condition, but it did not have a copy of Mac OS X installed. The previous owner had used the tower as a (shudder) Windows XP machine and erased the Apple development software. Noooooo!!!!
Finding a copy of the necessary software and then getting it to run on this system proved a bit of a challenge. That’s an understatement. These puppies require serious determination to bring back to life.
The magic system necessary is Mac OS X build 8b1025. After a few months I was lucky to get help from fellow Mac collector (and Prototype Man) Henry “Hap” Plain, who found a copy after locating a working DTS himself. But making drives from the disk image files he sent was unsuccessful, I couldn’t get my machine to boot. Multiple swapping of hard drives followed. After several tries we resorted to shipping drives across the country, and that finally worked. At last the mythical 10.4.1 on Intel was running live in front of me!
But I couldn’t duplicate the setup for backup purposes. This is an important part of keeping vintage computers working. Clones made of the startup disk would not boot the machine, they stalled at a black screen with a blinking cursor. More weeks of experimentation. More hard disks in and out. Let me tell you the drive slots on the G5 (err, DTS) tower are really annoying to deal with, they make me appreciate the Mac Pro design even more.
Damn it Apple, why are you making this (never-intended-to-be-released-to-the-public) system so difficult to restore? Never mind, don’t answer that.
Eventually Hap managed to locate an image of the actual 10.4.1 install DVD that shipped with the towers from from Apple (I’m very jealous of his connections). This works better: with the DVD you can easily install OS X on the hard disk and reliably make the DTS come to life. But wait! Don’t put that installer away after installation, it also contains a boot loader necessary get the hard drive up and running. I’ve found that I need to keep the DVD in place in order to boot up the machine, otherwise it’s back to a blinking cursor.
As noted, this is not your Grandfather’s Macintosh. DTS, welcome to the VMM.