History
Motorola's third generation PowerPC chip (the PowerPC 750, aka G3) formed the heart of Apple's new G3 series of machines. With the new CPU at its core, Apple created a new motherboard which incorporated a new high speed data bus to make sure that the G3 wasn't crippled as had been the case with other machines in the past.
Having been a big advocate of the PowerPC architecture, the G3 was specifically designed around the way that Mac users worked and the result was a chip that outperformed the existing PowerPC 604e even at lower clock speeds (tests carried out at the time showed that a G3 clocked at 233MHz was 22% faster than a 604e clocked at a similar 233MHz). It wasn't just pure speed that helped make the G3 the fastest CPU in the Apple arsenal but Motorola had designed the chip in such a way that it could make extensive use of 'backside' cache - which could communicate directly with the processor at extremely high speeds.
The result was the G3 (machine) which shipped in either a desktop or a tower form factor. Neither was revolutionary in terms of design (the desktop used the existing 7200/7300 case and the tower used a shortened version of 8600/9600 case). Shipping with either a 233MHz or 266MHz G3, the desktop version found that the new motherboard was so small that the hard drive could be positioned deeper inside the machine leaving a spare drive bay, into which Apple fitted an Iomega Zip 100 drive (to complement the 'standard' CD-ROM and floppy drive).
With no actual onboard audio, the desktop had a 'personality' slot positioned next to the 3 PCI slots and into this went the 'personality card', adding the all important audio aspect. It left the way open for expansion/upgrade in the future but most users were more than happy enough with the 'standard' option (Note: The G3 tower's 'personality card' also featured video in and out in addition to audio). Elsewhere onboard graphics came courtesy of ATi but the machine included a SO-DIMM slot allowing the video memory to be upped far more easily than the old proprietory VRAM that had been used in the past. Note: The G3 desktop included 3 DIMM slots for main memory but they required the use of 'low profile' sticks of memory - important when upgrading.
The Power Mac G3 may not have blown the world away with its looks being nothing more than a recycling of older cases but performance wise it was supremely impressive. It's use of an IDE hard drive (in favour of the die-hard SCSI system) allowed plenty of scope for bigger and faster hard drives to be fitted but Apple wisely retained a SCSI bus to allow those external old devices and drives to be easily hooked up.
Despite it's dull and boring looks, the Power Mac G3 was something that was missing from the museum but an office clearout meant that one became available at a price that was impossible to refuse: free. I landed the 'desktop' version but first signs weren't good. Yes the machine powered up but the hard disk just sat there clicking and the flashing disk icon meant that something was probably amiss. But this was an office clearout and the company's IT manager had wisely scrubbed everything. In went the Mac OS CD and we're up and running again.