Featured Mac: The Sonnet-enhanced "Yikes" G4.

So, as of this day, I am going to be periodically blogging a writeup with pics where possible on a different Mac or piece of Apple-hardware from my decidedly large collection. Given this is some semblance of an old Mac blog, this seems like something worth doing. 

As it is arguably one of my favourite Powermacs of the New World era, and has well and truly stood the test of 15 years, it seems fitting that the first featured machine should be my trusty, only recently retired Powermac G4 (PCI graphics), a machine known to most aficionados for many years now simply by it's internal Apple codename, "Yikes!" and the first of a long line of Apple pro-towers  to use the well-proven PPC 7400 CPU, which still had derivitives in use on Powerbooks and the Mac Mini right up into the mid-2000's, long after the monster 64-bit G5 took pride of place as the company flagship for the pro-est of pro-users.

The "Yikes" G4 was modelled very closely after the "Yosemite" (Blue and white) G3 Powermac tower which came onto the market in 1999 as the first high-end Macintosh to use the "New World" architecture and conform to the new "look" Apple had pioneered with the iMac... More on the G3 will come in another post at a later date, but suffice to say when I say the Yikes was modelled closely on this machine, I mean they are very nearly identical, right down to logic board design, such that I have always referred to the Yikes item as being essentially Rev. 3 of the Yosemite G3 logic board. The only physical difference is that the G4 board has all ADB componentry and the ADB port itself deleted (but all the blank pads are still there), and the Firmware has code to allow the machine to recognise and work with the G4 processor, which fits into the exact same Zero Insertion Force (ZIF) Socket as the G3's used in previous PPC 750-based desktop machines. And this is piled into the exact same "El-Kapitan" style case as the Yosemite G3, except that with the advent of the G4, came the start of the "graphite era" where the rather loud blueberry and white colour scheme and kind of cheesy but cool "G3" label under the translucent white side plastics was toned down on 3 generations of G4 tower by a far more clean-cut, professional looking scheme with a graphite front, top amd rear bezel, graphite side logo's and clear transparent handles, feet, and sides, but with the sides being painted white on their inner surfaces, all of which made it look like the powerful machine it was...

 Not bad to look at, huh? I thought not either!

The only major drawback of the new G4 was that, as it was rushed into production on the existing "Yosemite" platform, it lacked an AGP port which by that point in time was getting to be common-place on most mid-level and higher end IBM-compatible mainboards. Whilst, the 66mhz PCI-slot was adequate, it was still a decidedly unfavoured limitation by virtue of it's comparitively slow speed as compared to AGP, and simply because AGP was seen as the way forard, meaning that  as the years went on, the development of PCI graphics controllers rapidly came to a halt as the bus became obsolete for this purpose. Nonetheless, the ATI Rage128 with 16Mb of VRAM, whilst no speed demon, was a capable enough controller for the time. All the same, the Yikes gained a stigma as "the slow G4" and has never been particularly revelled among the Mac community, as it really was just a borderline obsolete machine with a cutting-edge CPU slapped in it... It didnt even have an onboard Airport card slot, whilst the low-end of the product line, the iMac even had one (unless you bought the really cheap and nasty 350mhz model without firewire), and the Powermac also had no support for booting off Firewire devices. The real celebrating happened not even a year later when the "real" G4, the Sawtooth, entered the market. It did so sporting faster CPU options, and now had AGP, Airport-connectivity, target-disk mode, firewire-booting, a doubled RAM-ceiling, and later on even a dual-CPU option... the moment it was on the shelves the Yikes became an important but slightly embarrasing piece of Apple history.

Anyway... here is my particular setup. Has been decluttered a little since this 2013 photo.

I originally procured this machine a fair few years ago as a G4/350, with 128Mb of RAM, the original 10Gb HDD still in place, CD-ROM drive, stock video controller... pretty uninspiring, all told. These days it is running a 500mhz Sonnet Encore CPU, which is the fastest CPU these boards will support off the shelf, maxxed out at 1Gb of RAM, and  running 2x now quite aging 40Gb drives which were carried over from the G3 which this replaced.  There is now also a DVD burner which is actually an OEM Superdrive removed from an eMac that I picked up specifically to scavenge parts from. In the internal pic you will see a third hard drive in the very front mounting bay, which is a backup of the main drive that and normally left unplugged unless being backed up to or restored from. It has both 10.3.6 and 10.4.2 installed but I usually run it on Panther only as its fast on these machines and simple, whereas Tiger contains a lot of bloatware that really does knock the comfortable usability around. I also used to have a PCI SCSI controller in this G4 but I turfed it out and put it in my G3 as having it installed actually slowed it down... that and I never used it anyway. The monitor is a gargantuan Apple Studio Display 17" which uses a beautifully crisp, sharp, and nearly flat Mitsubishi Diamondtron CRT tube, itself based on the Sony Trinitron technology. These are a fantastic looking display when functioning, but unfortunately, they do tend towards eventually failing due to faulty flyback transformers... this begins as an audible snap and flicker every so often... sometimes only once every few hours. But eventually the screen will just give up and display no picture, which is a shame. They really are one of the nicest looking CRT displays produce in any case. This monitor was at one point run off an ATI Radeon 7000 Mac Edition 32Mb  graphics controller however this unfortunately burnt out and I no longer have a need for such a fancy card, so I simply reinstalled the stock 16Mb Rage128 unit.

Some things to note about the Yikes are the following:


> It has a maximum RAM capacity of 1Gb of PC-100 or faster SDRAM. At this, I will also say, do NOT use the 168-pin DRAM from an Oldworld Mac, or it will blow up. Also, don't bother trying to use PC-66 SD-RAM as it is simply not fast enough for the  system bus.

> the Yikes can recognise a maximum of 120Gb per hard drive, and will support TWO hard  drives on the internal primary IDE bus. There is also the ability to address a slave drive on the secondary IDE bus, and a drive bay underneath the optical-drive  which will accomodate a hard drive... DO NOT DO THIS HOWEVER, as it is designed specifically for a ZIP drive which was a factory option. This secondary IDE channel is only ATA-66 so will be slower in any case than the primary channel. Furthermore, the buildup of heat generated by a hard drive operating in the ZIP bay constantly can drastically reduce the life of both the hard disc and optical drive. The other issue is that most Mac's of this era can only boot from a CD-ROM drive that is set as a master device on any bus. Why is this a problem you ask? why not just have it set as a master then?... Well... the reason is that if you have the CD-ROM drive set as a the master device on the secondary ATA bus, and have a hard drive as a slave, the Mac will not search for and detect a slave drive UNLESS it finds an actual volume in the CD-drive first at boot-up. If there is no CD in the drive, then the machine will skip Slave detection and the hard drive will be unmountable. Conversely, if you set the CD-ROM to slave, this problem is alleviated, however your CD drive cannot be used as a bootable device.

> Yikes uses most of the same case plastics as the Sawtooth, with the exception of the rear panel. The chassis of the Yikes tower is close enough to identical to the Yosemite to be interchangable, all case plastics are interchangable between Yikes and Yosemite  as are PSU, and with a Sonnet Firmware flash, a Yosemite logic board can also be used with a G4 in a Yikes in the rare event of board failure.

> The Yikes and Yosemite boards use jumpers in a plastic block (under the WARRANTY VOID sticker in the internal photo above) to set the CPU multiplier in increments of .5 from 3-5 times the 100mhz system bus speed. This makes overclocking theoretically possible, and at some point I will dedicate an entry to this topic. Some CPU cores will respond more successfully to overclocking than others... some will simply not overclock stabley. As a general rule of thumb +50Mhz is about the stable limit if any, and most *stock* CPU's will not run stable or at all on 500mhz setting. The Sonnet Encore however, uses a core rated to at least 500mhz. Please do not touch this jumper block if you do not have a sound knowledge of what you are doing, as you could render your machine inoperative.

> You will find under certain circumstances that a Yosemite/Yikes machine will refuse to turn on or boot after having RAM changed, CPU swapped, PCI cards added, drives... hell, you can sometimes sneeze and it will decide its not going to boot up. This is often mistaken for a critical failure, but usually isnt. Simply reset the cuda using the button on the logic board, that should fire it up, if in an attempt to boot, it shows no display, or turns on but does not bong on startup or do anything, hold in the interrupt button beside the reset button whilst you power up the G3/4 until you here a long, low beep. Reset the system immediately to a PRAM reset (Opt+Cmd+P+R)... reset it twice then boot to open firmware (Opt+Cmd+O+F held in straight after powerup). WHen you get th white OF screen with a commandline prompt, type the following commands in order with each followed by pressing Return.

reset-nvram
set-defaults
reset-all

The machine should usually boot normally after this procedure.

> Finally, if you intend on using Firewire regularly, I would highly recommend sourcing a compatible PCI Firewire card and using that, rather than the inbuilt ports, as the ports are rather fragile and break in some machines, and the controller itself can be rather flakey after some use.

Anyway... That's me done for this morning! I will definitely be doing a writeup on more Yosemite/Yikes stuff soon, namely overclocking. Watch this space!

OMT