iMac G4

In 2002 Apple released the successor to their all-in-one computer, the iMac G3. Originally named the “New iMac” the PC would eventually be known as the iMac G4. The iMac G4 was extremely futuristic looking for it’s time with the entire motherboard and other components being housed inside a dome case. Coming out of the top of this dome was an adjustable metal arm and a TFT active matrix LCD screen with a native resolution of 1024 x 768. This was still a era of large heavy CRT monitors and seeing an LCD still felt pretty futuristic. In today’s article we will be looking at the 800MHz model which is the second of the four revisions Apple made of the iMac G4.

Even if your not an Apple fan you have to appreciate the industrial design and ability to fit everything into a small 10.6″ dome case. Even in 2019 as I write this article the iMac G4 wouldn’t look out of place on a sci-fi TV series taking place in the future home or on a starship.

Of course there is a price for this compactness and design and I’m not talking the dollar amount Apple wanted for one. I’m talking about expandability which is obviously severely lacking with the G4.

The front of the dome has no visible buttons or LEDs, just a shiny Apple logo and a slot for the optical drive. The optical drive in my model is a CD-R / DVD combo drive but the drive did vary by model.

Side shot

Full rear shot

On the back of the dome we have an array of different connections for connecting your G4 to the internet as well as other peripherals.

All the way, barely visible, on the left side we have a Kensington security lock for securing your iMac to some object so whomever doesn’t walk away with it. Next to this we have a standard 3.5mm headphone jack. The next jack looks to be another standard 3.5mm audio jack but it is not. This is actually a special audio jack for a set of Apple Pro speakers. The jack is a little smaller then a standard 3.5mm jack and it also delivers power to the speakers. I unfortunately do not have a pair of these speakers but many consider them some of the best speakers ever made for any Mac computer. Following this we have two firewire 400 ports and an Ethernet jack. In the center we have a three pin power connector followed by a modem, three USB 1.1 ports and finally a mini VGA output port. The port supposedly only mirrors the main display but still handy if your having issues with the built in monitor.

To access the internals of the iMac there are four small screws on the underside of the base.

Removing the metal base plate gives access to the airport wireless card, or if you don’t have one, the port to install it. To the right is a 144-pin SO-DIMM RAM slot. This RAM is the smaller style SDRAM more commonly found in things like laptops. This slot will accept up to a 512MB stick of PC133 memory which is what I have currently installed. The iMac G4 can accept up to 1GB or RAM total but the second RAM slot is not as easily accessible. Later versions used DDR memory and had a maximum limit of 2GB..

After removing several more screws on the base of the G4 you need to carefully pry the two pieces apart. Even with the screws removed it may take some effort as there should be thermal paste still bonding the two haves of the case together.

Here are the two halves separated. The upper half houses a fan and speaker as well as both the CD/DVD drive and hard drive above that. My 800MHz G4 came with the stock 5400RPM 60GB hard drive and OS X 10.4.11 installed. This hard drive can be upgraded to a larger size and can even be replaced with an SSD (via an adapter) if so desired.

Now lets take a look at the interesting part, the motherboard attached to the base of the g4.

1) CPU – My model features an 800MHz Power PC G4 but earlier models featured a 700MHz CPU. Later models went all the way up to 1.25GHz. There is no fan on the CPU but the heat sink is interesting on these models as it attaches to the side and makes contact with the upper half via thermal paste to use the entire case as a heat sink. This heat sink is more significant on the faster models. A metal clip holds the sink firm against the CPU but can easily be removed with the help of something like a flat head screwdriver and a bit of force though be careful not to gouge the motherboard or slip.

I do tend to like the Power PC chips and the 800MHz is sufficiently powered for the time though of course you’ll get more gaming mileage from a 1 or 1.25GHz model.

2) RAM – The second RAM slot is located on the upper half of the motherboard and uses a standard 168 pin DIMM slot. The slot on mine is also populated with a 512MB PC133 stick bringing my G4s memory up to the 1GB limit. I do understand Apple was working with space limitations and had to be creative to fit everything but it is an annoyance that one can only easily access half of the RAM sockets for upgrading without taking the computer apart. The difference in form factor could also potentially confuse less tech savoy consumers looking to upgrade their iMac G4s memory.

3) Video – I did not remove the small passive black heat sink to confirm but I’m almost 100 percent certain that lying underneath is the iMac’s Geforce 2 MX video chip. This model as well as the earlier iMac G4 also used this chip along with 32MB of non-upgradable video memory. Later models used the Geforce 4 MX chip as well as FX 5200 Ultra chips along with more memory. The Geforce 2 MX in the 800MHz here was not a high end or enthusiast oriented card but was a sort of cut down Geforce GTS with performance numbers a little higher in general then the older Geforce256. It did run cool and featured some advanced features for the time such as T&L (Transform and Lighting) capabilities making it a good choice for a non gaming oriented all in one machines like the iMac G4.

Next to the GPU chip we also have a small daughterboard like card. I believe this card has chips controlling the wireless and networking functions of the iMac.

4) Battery – This is the typical PRAM battery found ubiquitously in older Macintosh PCs. It’s always a good idea to change this battery when picking up an old Mac.

5) Various connectors

Above where the heat sink arm meets the upper case we have three connectors for interfacing with the upper half of the iMac. The smallest connector on the lower right is a power connector while the one above it is a standard ATA-66 IDE connector for interfacing with the CD/DVD and hard drive. The last connector strongly resembles a floppy drive connector but it is not. I believe this is just the interface between the monitor and the motherboard video and connects with a female connector on the upper half of the case.

The iMac G4 is a very futuristic design that even in 2019 I feel would fit in on the set of Star Trek or some other sci-fi production. As an everyday PC in its time it probably made a half decent space saving and fashionable family computer for tasks such as surfing the web and doing things like homework. As a gaming computer for a retro gamer though I find it very limited. The CPU is adequate but the Geforce MX is more suited for older 90’s games rather then early 2000’s mac titles. The RAM is a bit annoying to upgrade requiring you to open the case and upgrading in general is very limited. Unless your very short on space, only looking to play older 90’s Macintosh games or just love the stylish futuristic look of the iMac G4 your much better off with any of the Macintosh G4 towers such as the Digital Audio G4 or the Mirror Drive Door G4 towers, at least as far as expandability and gaming go. If you must have that iMac G4 look though there are always the more capable 1 and 1.25GHz models that should offer more in the way of early 2000’sOS X gaming capabilities.

G4 Macintosh (Sawtooth)

On this blog we have already taken a look at two models of the Apple G4 Macintosh line. In this article we are going to take a brief look at another of this line. The Macintosh G4 “Sawtooth” also referred to as the AGP G4 due to its addition of an AGP slot for video.

The Sawtooth as we will refer to it uses the same style case and color scheme as the Digital Audio G4 that I covered earlier as well as the entire early G4 line. Released in 1999 the Sawtooth was a modest improvement over the earlier “Yikes” G4 with an AGP slot for video as well as faster ATA controller for IDE devices and the option of some faster video cards as well as faster CPU speeds.

The front is identical to the earlier models with the center speaker and power button as well as the smaller reset and debug buttons on the lower section. There are two bays, one 5 1/4  and the lower bay being 3 1/2. Mine has a DVD drive installed as well as an optional ZIP drive.

Turning the Macintosh around we see the PSU connector as well as four expansion slots on the lower portion of the case.

On the upper half we have our various connectivity jacks and ports.Closest to the top we have two Firewire 400 ports with a 10/100 Ethernet jack below that and then below that we have two USB 1.1 ports and finally two audio jacks for speaker and / or microphone. We also have a jack for a modem to the right.

Like the other G4 Macs the case opens very easily by pulling on a handle on the side. Here I have all the expansion cards removed as to give a better view. Up top we see the power supply as well as the two drive bays. The bays are actually one single piece that slides out by removing the front panel and undoing two screws. The lower bay appears to be 5 1/4 at a glance but it’s really a 3 1/2 bay. Mine originally had a hard drive installed in it for some reason.

The G4 Macintosh actually has ample room for hard drives and mine came with six hard drives installed. Possibly the previous owner was running a RAID array. I took out most of them but left in two. One is a 400GB and the other is 250GB. I left the OS that was installed though which was OS X 10.2 though I believe the original OS shipped was 8.6.

Now lets take a better look at the motherboard.

Compared to a PC motherboards I always found Macintosh motherboards from this time to look rather sparse and boring though this may be attributed to having components on the underside of the board. This motherboard like the Yikes model before it and the Gigabit Ethernet model after run on a 100mhz front side bus.

1) CPU – All of the original model G4 Macs run on the Power PC G4 (7400) CPU.  The CPU in this machine is a 450mhz version with 1mb of L2 cache but they also came in speeds of 350mhz to 500mhz. The 450mhz would be the middle range option and is probably comparable to an earlier Pentium III in performance.

2) RAM – There are four slots present designed to handle up to 2GB of PC100 SDRAM. stock though the most the machine usually came with was 256mb. Also earlier OS’s which originally came loaded onto the Sawtooth can only detect up to 1.5gb

3) Internal Firewire. The Sawtooth G4 has an interesting internal connector not present on the earlier Yikes models nor the later Gigabit Ethernet version. This is a Firewire 400 jack on the lower right corner of the motherboard presumably to power an internal Firewire hard drive.

4) Wireless airport card connector for attaching a wireless card. This was a feature not present on the earlier model.

5) ATA connectors – Two ATA66 connectors for attaching up to four IDE devices such as CD drives and hard drives.

6) CMOS battery – Is the standard 3.6 V lithium battery to save settings. Like all Macs the death of these batteries tend to cause more issues then what I see happen in PC’s. If your having odd instabilities replace these things first.

7) ATX power connector

Finally lets take a look at the expansion slots and cards I have installed.

The Sawtooth comes with three 66mhz PCI slots which will accept your standard PCI cards as well as special cards meant for the faster 66mhz PCI slot. Also new to this model over the Yikes Macintosh is the x2 AGP slot for a dedicated video card.

Video – The video card I have installed is an AGP ATI Rage 128 Pro card. This would of been the stock video card to come with this G4 though some models also came with non Pro versions. These cards came with 16mb of video memory onboard. I think the Rage 128 Pro is a decent card for the time and these were found in virtually all Apple Macintosh machines at the time. They have decent performance compared to something like the TNT2 as well as good compatibility with older titles. The video out options on this particular card are also nice offering standard VGA as well as DVI and S-video. This card does seem to run out of steam fairly quickly when you start running games post 2001 or so. Id recommend it for late 90’s Mac games but if you looking to upgrade this card maybe should be close to top on the your list for replacement.

SCSI was also an option on these Macs and many long time Macintosh users were still quite accustomed to the SCSI hard and CD drives. My machine came with a PCI Adaptec SCSI controller which I suspect was installed stock. I was able to use this card to replace the hard drive in the ZIP drive bay with an actual purple face plate SCSI ZIP drive although stock these machines used IDE ZIP drives with a face plates matching the translucent blue plastic.

CPU UPGRADE

I did also happen to acquire a Sonnet Encore ST/G4 upgrade CPU that I wanted to test out on this machine. Mine is a whopping 1.7ghz upgrade but they also made a 1.8Ghz upgrade chip and possibly faster. Installation was fairly easy and saw a massive speed boost over the 450mhz G4

I did notice that OS 10.2 did identify the CPU as a G3 though this didn’t seem to really affect anything.

Another upgrade I tried out as adding a PCI ATA133 card to match with the installed Maxtor ATA133 hard drive. This created noticeable faster booting times.

All an all another solid G4 machine from Apple. The Sawtooth does a modest job of improving on the Yikes G4 (a machine I hope to one day cover) but doesn’t offer anything to dramatic. Again, this is machine would certainly make a nice 90’s Mac gaming rig with a CPU that falls into the area of being capable but not to fast. The case is also rather nice being built quite solidly compared to earlier “brittletosh” cases and is also super easy to access and work on. I’ve never had any issues with the G4 processor and its always a treat to work with. These machines can also be found very cheaply so don’t hesitate to pick one up.

 

G4 Macintosh (Mirror Drive Door)

In my previous article I talked about the Macintosh G4 and specifically the “Digital Audio” model. This time I’m going to talk about another G4 Mac sometimes referred to as a DRR G4 but more commonly known as the MDD or Mirror Drive Door model. Looking at the images above and below it becomes fairly obvious how these machines got their nicknames.

The case overall is basically the same as the Digital Audio versions case and in fact all the G4 tower PC’s are similar with exception of the face and back. The case color scheme is more silver this time around as well as the cases area of the two drive bays has a mirror like plating, hence the name. This is actually quite reflective and I guess is useful to see if your being snuck up on while browsing on OS X or as a impromptu weapon against Medusa attacks. Also on this mirror finish section we have the power button at the top which glows a nice white when powered on as well as a welcomed frontal audio jack for headphones. The speaker is now placed at the very top with four decorative vent looking recesses at the bottom. Missing are the reset button and programmers button found on the Digital Audio and earlier G4 tower cases.

The rear of the MDD is the opposite layout of the earlier Digital Audio case. This time the expansion bays are at the top while the various ports and jacks are near the bottom.

The available ports are exactly the same but in a different orientation. Two USB 1.1 and two Firewire 400 jacks followed by Ethernet and modem jacks and finally an audio output jack and a jack for those Apple high definition speakers. The only addition is an audio input jack next to the audio out.

Opening the case is the same as before and super easy with a side handle that pulls up and away.

Inside it’s basically a reverse layout of what we saw in the Digital Audio machine.

On the section of the case that does not fold out we have two full 5 1/4 drive bays for optical drives as well as a fan and three spots for hard drive mounting. Two 3 1/2 inch HDD bays under the 5 1/4 inch bays and one vertical oriented 3 1/2 inch HDD bay to the left under the power supply. I have two hard drives currently installed. One 80GB drive that holds Mac OS X 10.5.8 and a second 180GB drive for data.

Like other G4 motherboards the MDD motherboard has quite a few chips soldered on underneath making the board look slightly bare from the top.

1) CPU – The MDD model G4s came with many CPU options up to dual 1.42ghz G4 PowerPC 7455 chips. Mine was the lowest powered model and came with dual 867mhz chips with a 133mhz front side bus. Note that many models in the MDD line came with dual CPUs on a sort of CPU module. As I said previously in articles its hard to compare the power PC to the far more common Intel X86 CPU’s in speed but this would roughly be equivalent to a Pentium 4 or maybe a 1.4ghz Tualatin PIII but this is only a rough guess.

2) RAM – four slots supporting up to 2GB of DDR RAM which is also why this model is also sometimes referred as the DDR G4. Unfortunately the Power PC 7455 can only use at most 50% of the DRR RAM bandwidth meaning there is no improvement over the previous models and their PC133 SDRAM as far as memory speed is concerned.

3) Four 64 bit PCI slots (which work fine with regular PCI cards) as well as one x4 AGP slot for video. Keep in mind that if your using a x8 AGP card whether a MAC card or a PC card that has been flashed with a mac BIOS you need to disable pins 3 & 11 to get video. This applies to all G4 Mac’s with the exception of the AGP 2x Sawtooth models. This issue is due to apple using the at the time unassigned pins 3 & 11 for the “ADC” apple monitors connection. When AGP x8 came out those pins were suddenly used for something else so basically they wouldn’t run on a G4 Macintosh. The way around this is to disable the pins completely either by taping over them or cutting the traces making the card AGP x4.

The card I’m using in this machine is a Geforce4 MX. Not a particularly interesting card but it more or less does the job. The MX was a budget card and less advanced then even the preceding Geforce3. For me it’s enough since I really only use this machine for one game and messing with OS X but the MDD G4 can support up to a Geforce 7800 GS with the earlier mentioned Pin modification.

4) Wireless airport adaptor for wireless internet

5) IDE connectors – There are actually three IDE connectors but one is obscured behind the huge CPU heatsink. The one located behind the heatsink is an ATA-100 connection intended for your primary hard drive.

The two connectors located at “5” are an ATA-66 connector for two secondary hard drives and a ATA-33 that is intended for the optical drives.

Regardless I have a separate Sonnet ATA-133 PCI controller card installed in my machine for the optical drive and main hard drive while my secondary hard drive is attached to the ATA-66 labeled connector.

6) CMOS battery used for saving settings.

Upgrading the CPU

I decided to upgrade the CPU in my MDD Mac since the CPU it came with was barely what I needed to do what I wanted to do with this machine. Third party CPU upgrade kits seemed to be overpriced so in the end I decided to go with a cheap $25 upgrade to a single 1.25ghz CPU. Now the value of this upgrade is somewhat debatable since I was going from a dual CPU configuration to a single CPU and OS X can take advantage of dual CPUs but my main purpose of this rig was to play a few select games which didn’t really take advantage of dual CPU anyways so I figured the 383mhz bump was worth it.

When considering a CPU upgrade for any G4 Macintosh keep in mind the CPU modules are not compatible across models so make sure the CPU your looking at is specifically for your model, for instance for a MDD model or Sawtooth G4.

I also wanted to (and needed to with this CPU upgrade) bump the front side bus speed up from 133mhz to 167mhz which required a small modification to the motherboard.

First disconnect any cables from the motherboard and then remove the currently installed CPU which can be done by unscrewing the various screws holding the heatsink on and then gently disconnecting the CPU module from the motherboard. It will look like this with the module removed.

next unscrew any screws fastening the motherboard to the case and remove. The modification we need to do to enable 167mhz FSB is the desoldering and removal of a resistor on the underside of the motherboard.

The piece we need to desolder is labeled as R676 and is located near one of the corners of the large black heatsink.

Desolder this component and that’s it. You can now install a faster CPU and have a slightly higher FSB.

The final step is to reassemble and install the new CPU. Here is my 1.25ghz G4 CPU module before installation and reapplying the heatsink.

And lastly booting the machine and checking the system information to confirm everything.

I like the MDD G4 Macintosh. It’s super easy to work on and plays the few early 2000 OS X exclusive games I need it to play just fine. It does have its issues though. It’s a shame there was no real improvement with the DDR RAM being used over the older PC133 SDRAM. Also upgrading the CPU if you have an early model like mine can be a small chore requiring a modification not to mention the modification needed to use a more powerful AGP video card. Another problem is the fan. This machine can be pretty loud and I noticed it is significantly louder then my Digital Audio model G4. For me the fan isn’t to loud and doesn’t come anywhere near the noisiness of my dual Tualatin rig but I can see how it can annoy some people and the noise level did seem to be a common complaint when I was doing research on the model. I would still recommend a MDD model though if you just wanted to casually mess around with those few early 2000’s OS X games and you can pick up a rig cheaply.

G4 Macintosh Digital Audio & Quicksilver

The G4 Macintosh was produced between 1999 and 2004 in three main distinctive variations known sometimes as the “original G4’s” or “Sawtooth” models, the “Quicksilver” G4’s and the “Mirror Drive Door” or MDD G4’s. Even among these there were motherboard variations. For instance early models of the “original” line lacked an AGP slot. The G4 I’m going to talk about today is a sub model known as the “Digital Audio” G4 and falls somewhere between the original line and the Quicksilver models. Basically It has the motherboard of an early Quicksilver model in the case of the original line.

To be honest I’ve grown kind of fond of the G4 towers over time. They tend to strike a sort of balance between the good things about apple such as design and the Power PC CPU and a IBM compatible such as expandability and more standard ports and drives.

The case design for all the G4’s is more or less the same basic design with most of the variations concerning the color and style of the frontal bays. The digital audio G4 uses the same case as the Sawtooth line and is a pleasant white/bluish color. There are also these handle looking things that are on every corner which in all honestly are nice for assisting lifting and moving the relatively heavy tower. On the front we have two 5 1/4 bays.

Internal shot of the two bays.

one usually sports a DVD/CD drive as mine does and the other sometimes a 100mb ZIP drive depending on your model. Mine obviously lacks the ZIP drive but one can be added easily enough.

Also on the front we have a grill for the built in speaker as well as a power button that glows a nice white when powered on as well as a programmers button and a reset button beneath that. The programmers button can be used to bring up a console window for debugging and can also be used to update firmware.

Under the fan slot we have a standard power jack and to the left we have our built in ports. At the top we have a modem jack and two audio ports. The top jack is a standard headphone jack and below that is an apple speaker mini-jack for high fidelity apple speakers. Further down we have a Ethernet port followed by two Firewire 400 ports and a pair of USB 1.1 ports. Below that we have five slots for internal expansion cards. The top one is taken up by my video card since the G4 machintosh’s do not have built in video. further down I added a Firewire/USB card for more connectivity.

Unlike many of the earlier Mac’s I’ve reviewed here the G4 uses a seemingly higher quality plastic and a lot more metal so the case feels much more sturdy and less prone to “brittletosh” issues. Opening the case is getting inside is ridiculously easy and may be the easiest time I’ve ever had getting into any PC or Mac. All you do is lift the handle on the side of the case and….

Once open you have almost full and unimpeded access to the board. At first I thought the motherboard seemed very barren and unpopulated but many of the chips and capacitors are actually mounted on the underside of the board. There are also three spots on the bottom of the case for mounting hard drives. Currently I only have one lowly 40GB IDE drive mounted.

On to the motherboard.

1) CPU – The Digital Audio G4’s came with a variety of CPU speed options starting at 466mhz. Mine is the highest end model sporting a 733mhz PowerPC 7450 processor sometimes refered to as a G4e (enhanced) as it is a redesigned and improved version of the G4 CPU. Its very hard to find CPU comparisons between PPC and Intel x86 CPU’s on the web but I would wager its perhaps equivalent to a faster Pentium III. This motherboard is running on a 133mhz front side bus.

2) CMOS battery – Is the standard 3.6 V lithium battery to save settings. Like all Macs the death of these batteries tend to cause more issues then what I see happen in PC’s. If your having odd instabilities replace these things first.

3) RAM – Three slots for SDRAM supporting up to 1.5gb of PC133 RAM

4) Expansion slots – four 64 bit 33mhz PCI slots and one AGP x4 slot for a video card.

Video – The Digital Audio G4’s came with one of several video cards. Mine came with an AGP ATI Rage 128 Pro with 16 MB VRAM. Keep in mind that if your using a x8 AGP card whether a MAC card or a PC card that has been flashed with a mac BIOS you need to disable pins 3 & 11 to get video. This applies to all G4 Mac’s with the exception of the AGP 2x Sawtooth models. This issue is due to apple using the at the time unassigned pins for “ADC” apple monitors connection. When AGP x8 came out those pins were suddenly used for something else so basically they wouldn’t run on a G4 Macintosh. The way around this is to disable the pins completely either by taping over them or cutting the traces making the card a AGP x4.

This card is a Macintosh version so it comes with both a VGA port and an Apple Display Connector port. Its not really the most exciting card but it does well enough for 90’s games and some early 2000’s games. Your going to want to upgrade though for any series turn of the century gaming though. Officially the Digital Audio models were sold with up to Geforce 2 or 3 cards installed (some conflicting information).

5) Wireless airport card connector for well….connecting to wireless devices.

6) IDE connectors – Two ATA-66 connectors for connecting a total of four IDE devices. In my setup I have my DVD drive connected to the onboard ata66 connector but I’m using an ATA100 PCI card to connect to the hard drive.

7) ATX power connector.

I haven’t really done much to this machine since I got it. I’m currently running OS X 10.4.11 which is the highest officially supported version of the OS.

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For comparison I also have a standard Macintosh Quicksiver G4. For all intents and purposes the Quicksiver is basicly identical to the Digital Audio except for the case and improved specs stock such as faster CPU and graphics cards.

I rather like the look of the front speaker without the grill.

On the read we have the same connections though my Quicksilver here lacks the modem. Finally a look at the motherboard which looks a little diffrent as far as some smaller compoents but has the same amount and placement of major compoents such as expansion slots.

I haven’t used this particular Mac much because I have a more powerful MDD G4 that I will eventually cover here that I use for present general early OS X stuff. That said I do like the Digital Audio G4. most of all I like the color scheme and ability to easily add a ZIP drive, even though I currently haven’t and probably will not.