Anniversaries and an iMac G4 "Sandy Bridge Mod" Pro Version?

I hadn't even realized that I failed to acknowledge an important anniversary.  The iMac G4 was introduced on January 7th, 2002 by Steve Jobs at the San Francisco Macworld.  The 20" was released later in November 18, 2003.  Then only 2 and a half years later (August 31, 2004) the iMac G4, with its sunflower inspired horizontal design, was discontinued in favor of the iMac G5's vertically oriented all-in-one.

Many reasons have been suggested to why this was done.  The cost of the neck, the difficulty in supporting increasing LCD sizes, and the cooling needs of the notoriously hot G5 processor.  I have been using one version of this as an external monitor hooked up to a mac mini and now a second version as a modernized all-in-one and it remains one of the most enjoyable desktop user experiences I have know, even 10 years later.

With my sandy bridge "genuine" mod my goal was to be as true to the original as possible, but I have been thinking about doing a version that has some extra features not found in the original.  Some of these may be possible, some of them are not.  To make extra room in the base, the optical drive will be removed.  So, I am contemplating doing a "PRO" version of the iMac G4 mod.  I have enough spare parts and I think this may be a fun alternative.  I will likely use the TMDS to DVI method and not the apple cinema display controller method.  The overall look of the iMac G4 will be changed (something I wanted to avoid in the previous mod).  Things I may add:

3M Touchscreen

• A Touchscreen: One of my favorite mods used a resistive touchscreen and it fits this form factor quite well.  However, I did not like the glare, resolution, or touch accuracy of the resistive touchscreen.  I have however located a capacitive touchscreen that should fit in this mod.  Its flaw is that it is somewhat thick and heavy.  An alternative may be incorporating optical sensors in the bezel.
• LED backlighting: This would be necessary to fit the touchscreen, but something that has been done in similar projects by JL7, and adds improved backlighting and power efficiency.
• Quad Core Processor: I changed from a mobile core i7 quad core to a dual core i5 as a result of both heat production and power consumption in my latest mod.  However, a quad core i7 machine is still something I would love to do.  As well as maxing out the RAM to 8GB.
• Native Power: Increased power needs would require a big power supply and the only one that could fit is the native supply which other modders have used.
• Better Cooling: Use of the native PSU would require shifting of the mobo downwards.  This as well as heat generated by the quad core processor and the PSU itself would require a much more powerful cooling solution.  At the very least a large active heatsink on the CPU and a 92mm case fan.  However, an intake fan at the bottom may be needed as well.  This will use of the space that was previously used by the optical drive.
• iSight Cam: in my G4/G5 setup, I use the iSight cam on the G5, but I have been wishing that there was one on the G4's LCD as it would be much easier to manipulate.  The microphone is already there, modifying the LCD enclosure to support an iSight may be possible.

iMac G4 iSight Mock-up

• Apple Modification: Just to visually delineate this, I was considering altering the apple on the base.  A light up apple or IR sensor are possibilities
• ???Improved Graphics: This one is difficult, although its something I would like to add, most of these small boards do not have PCI-Ex16 slots.  Even conversion of mini pcie is usually only to x1, and this makes it difficult to get much improvement over on chip sandy bridge graphics.  Fitting and powering a full size card would also be difficult.  I will continue to give this thought, but its probably unlikely.  Even if you wedge a mini itx in, you would have difficulty fitting even a low profile card in to the dome.  

Although this mod would involve tradeoffs including louder fans, loss of the optical drive, and loss of the exact iMac G4 appearance, there are clearly advantages as well.  The iSight, LED backlights, and touchscreen in particular are things I would love to add.  Any suggestions would be appreciated.

The KEEX-6100 ROARS!

Nearly Complete

Just a quick update on the Sandy Bridge ECX Board: KEEX - 6100:

Using the Unibeast Method developed by the amazing tonymac, installing Mac OS 10.7.2 is quite easy once you make a few modifications to the bios.

If you have any interest in hackintoshes then there is no better place than Tonymacx86

For this board make sure you:

1) Enable AHCI as per tonymac's instructions

2) Disable the Onboard Audio (it causes a kernel panic every time and drove me crazy until I realized what was causing it).  Even if this can not be fixed, it is not a big loss as the onboard audio is no better than USB audio would be

3) Set either the display port or HDMI (which ever you use) to Display option 1.  If you leave the LVDS as the primary and secondary disabled (default) there is a weird quirk where the image disappears after boot and only returns if you unplug and replug the monitor.

4) I am getting assistance in trying to solve this problem, but for now S3 sleep does not work.  Change BIOS power settings to allow for only S1 sleep, which works fine.

View of iMac G4 and Keex-6100

iMac G4 with TMDS to DVI, DC-DC upconversion

Lion (10.7.2) on the iMac G4's native LCD

The KEEX-6100 identified as a Mac Book Pro

As the KEEX-6100 uses a mobile chipset it was identified as the new MacBook Pro.  The chipset, processor, onboard intel graphics are all supported natively by Lion.

Gigabit Ethernet/LAN Works with simple kext addition.  The PCI-Express Broadcom Wifi Card works great.  Whats more is that you can hook this card up to the native Wifi Antenna (located outside the faraday cage, but inside the plastic dome), this gives a very strong signal.  Preliminary fit testing shows everything fits.  Only wake from S3 remains (wake from S1 sleep works fine as noted above).

I have put a card in the CF slot, which is only recognized when the computer's SATA settings are IDE and not AHCI.  Though this is as easy to change in the bios as boot priority, it is a little cumbersome.  I have put Windows 8 Developer Preview on the CF Drive and will see if dual booting is a possibility.

Over at tonymac x86 forum, a very knowledgable modder, offered to help with sleep and has himself gotten the onboard audio chipset to work (on a different board).  So, onboard audio ay in fact be an option. I am giving some thought to internalizing the internal board of the griffin powerwave adapter.  I have only the area between the bottom of the dome and the optical drive, but the board seems thin based on the size of the case.  I am going to hold off finalizing the rear ports until I choose which audio option to go with.

20" iMac G4 "Genuine" Mod - INVERTER SOLVED

So That Only Took Me A Year! It was January 8th, 2011 when I documented in this post on my blog my frustration with the 20" inverter and my inability to get it to enable the backlights on the native LCD in any kind of reproducible way.

I believed that the LCD itself would not pose a problem and I posted the TMDS to DVI pinout in this post, though had not been able to confirm it until now.  And yes it does work.

The Apple Logo on the ID Tech 20" Panel

I had devised a work around using the LCD controller from the 20" Aluminum Apple Cinema Display, the mod was shown in this post.  The controller worked perfectly with the iMac's native inverter and LCD (with one addition).  This mod hooked up to an external mini has become one of my most frequently used computers.  It has several advantages in that it is VERY STABLE.  The reason its so stable is that it really is an apple cinema display masquerading as an iMac G4.  While aesthetically perfect, I am reminded of this every time I open the display preferences and Cinema Display is shown in front of me.  As a Computer User - It's the perfect solution.  As a Computer Modder - I felt somewhat defeated, in that I wasn't able to solve the problem.  But there was another problem, this mod was complicated.  The neck had to be rewired and components from an expensive cinema display had to be used.  I knew that this mod could not be easily replicated.

When I finished my 17" STEP by STEP GUIDE.  I knew I was going to get questions regarding to 20" and if such an easy approach could be used.  However, because of my cinema display mod, I now had information about the inverter that I had previously lacked.  I have never owned a working 20" iMac G4 and was therefore making (supposedly) educated guesses, while trying to figure out the inverter.  A damaged inverter later, I realized this approach was not great.  With a working inverter via the cinema display's controller, I finally had voltages to check and use as a guide.

So, using my new technique, once the pins were free (The LCD was wired up in just a few minutes).  I then tried a few different things using my new information.  And for the first time I had a 20" iMac G4's native LCD and inverter display a backlit video signal through the neck (hooked up to a mac mini via DVI) using only wires, connectors and power supplies.  The power scheme is much more complex than the 17", this is due to the higher power requirements of the 20" LCD.  However, this uses the same method for the LCD as the 17" mod and is quite reproducible.

For those who have followed this blog, you know that this has always been a frustrating shortcoming for me.  It has been a long time, but I am so excited to be able to share this with everyone.

Lion's Desktop

Identified Monitor as "iMac"

Needless to say, I will be posting a step by step guide for this.  And this mod will be done to completion.  In addition, I believe that I have now found a home for my KEEX-6100.  This will now form the backbone for a new iMac G4 20" All-In-One.  I intend to document the process, including adding the computer to the base for those that wish to do something similar.

Again, thanks for reading!

Mini-itx Problems, SBCs and Embedded Boards

Base with Drive

When making an all-in-one you have to realize the base of the G4 is very small - Much smaller than you think.  The faraday cage inside provides all the real "support" of the base.  Unfortunately 4 steel "legs" make it even tighter.  Below the drive pictured here there is only about 1/2" inch.  The iMac was convection cooled so everything just stacked on top of each other leaving no room for airflow.  Below is how an atom mini itx board with standard fan and heatsink looks interns of thickness next to the original iMac G4's motherboard.  Remember the drive sits right on top of the motherboard - there is no wiggle room.

This standard size fan takes up much of the room that the drive occupied as well.  Even above the drive there is minimal room (enough for a 3.5" hard drive and then a fan.  The power supply was actually split in two and placed on opposite sides of the hard drive.

Without having to grind down the faraday cage even fitting in a mini itx is difficult.  You have to put it in at an angle, accessing the ports can be difficult.

Even when using just a mini itx board, no optical drive, no graphics card, just a small hard drive, there are two problems with creating a "powerful" system: Power and Heat.

By power I am referring to where the power source goes.  No atx power supply can fit in any way.  The existing power supply is not compatible with atx and regardless the 17" is only 160watts.  Pico power supplies are really the only option and these are limited to about 150 - 175 watts.  Remember, some of this has to go to power the display, support USBs etc.

By heat I am referring to the very poor air flow of the steel faraday cage.  The only air entry points are some slits at the bottom and holes at the top.  You would never, ever choose this as a computer case.  The mini itx has to sit at the very bottom (its the only place it fits).  So anything else you want to put in the case - wires, wifi, optical drives, ssds, whatever, has to go on top of the board.  This further blocks air flow.  Trust me, even with pristine wire management anything other than a very low power system is going to have problems.  So you are VERY limit din what can go on top of the motherboard.  If you are building a system just to show that it can power on, a "proof of concept" then you don't have to worry.  But, if you want a stable, reliable system that you can use daily, there is a better way.  There are actually two options:

1) Go Big: You want the system you want.  Dedicated graphics, optical drive, big power supply.  Then go external.  This is the way I went with my mac mini setup and I couldn't be happier with it.  I went dual monitors and was then able to use the base to house the optical drive and 20" monitor power supply.  Keep in mind the iMac is a desktop, you aren't carrying it room to room.  This makes upgrades a breeze and you are no longer limited by size, heat, or power.

2) Go Small: What if you could fit a motherboard at the top of the dome.  The CPU sitting right under the ventilation holes would allow for some airflow.  What's more, this would allow you to use the space below however you see fit.  In my all in one I went with a bluray optical drive.  There are compact options beyond mini-itx.  These are usually referred to as either Single Board Computers or embedded systems.  Although most of these systems are not available from usual vendors such as amazon, newegg etc, they are still easily to obtain commercially.  I have dealt with many sales reps from the companies I am going to discuss and they have almost universally been very helpful.  These boards are sometimes more expensive then their commercial atx counterparts, sometimes less.  They tend to use laptop parts (which tend to be lower power and generate less heat).  They usually have on board power options.  Their expansion options are usually very limited (but there is really isn't any room in the dome for expansion).  They are usually associated with low power platforms but are NOT limited to these.  Many form factors are available, but I am going to focus on those that have I/O that is familiar and compatible with commercial products.  So lets see what's available.

Zbox Nano

1) The ITX's

- A) Mini-itx (170mm x 170mm) (6.7" x 6.7") - discussed above

- B) Nano-itx (120mm x 120mm) (4.7" x 4.7") - These are sometimes available from standard vendors.

     - I for one am very excited about AMD's fusion platform.  

       The Zbox Nano relies on a Zacate E-350 APU which yields on board AMD HD 6310 graphics.  This is available as a barebones system and although it comes with the zotac case, it can be removed.  If a hackintosh is your goal, this won't suit your needs.  But if you want low power, but some graphics power consider this option.

- C) Pico-itx (100mm x 72mm) (3.9" x 2.8").  You may not believe it, but this is a legitimate option.

Pico-itx

      - While not my favorite platform, Intel's Atom, is certainly capable of being a machine capable of everyday, routine tasks.  And is available on most PicoITX bards.

Epic SBC

2) Industrial Computers 

- A) EPIC - Embedded Platform Industrial Computers (165mm x 115mm) (6.5" x 4.5").  These can blur the line between mainstream and industrial systems, but many have nothing but standard I/O and are have identical chipsets and features to the larger mini-itx boards.

      

3) Drive Sized Platforms

- A) 5.25" Embedded - (203mm x 146mm) (8" x 5.75") - designed to be the same size as a 5.25" drive.  Although longer then mini itx, its narrower shape is better for the iMac.  If you don't use an optical drive these may be considered (although they are on the larger size).  Available in everything from Atom, to Intel Core 2 Duo, to 1st and 2nd generation Core i processors.

KEEX-4030

- B) 3.5" Embedded/ECX - (146mm x 105mm) (5.75" x 4") - similarly designed to be the same size as a 3.5" drive.  ECX is an intel developed standard, meant to give the performance of mini-itx in a smaller form factor.  Similarly available in many varieties.  Global American again has a wide selection from Atom up to 1st generation Core i processors.  Two popular makers of these systems are Quanmax and Portwell.  Online distributors such as logicsupply.com offer these boards.  For my All-in-one I used the Keex-4030, a Quanmax Core 2 Duo Mobile Processor Board.  I found it easy to use and it delivered solid performance.  A second generation core i/sandy bridge mobo has been announced by Quanmax, but I have not found it available yet.

I would probably recommend either Nano-ITX or 3.5" ECX as they offer the best availability, standardization, and size to performance ratio.  Just remember that a non-standard board may have some quirks (proprietary connectors, limited expansion).  Do your homework first, before buying.  But there are plenty of options for small motherboards beyond mini-itx.

Completed Mod - Mac Mini with iMac G4 and G5 dual monitors

Original Dual Monitors with Mac Mini

New Setup with iSight G5, Mac Mini, and iPad

While the core components are completely unchanged from my previous 20" iMac G4 mod, this represents the completion of the overall setup.  I would highly recommend this to anyone in search of a "weekend hobby" who shares my enthusiasm for this generation of apple products.  Most people seem to be interested in the 17" mod, but as someone who has used both, I would recommend putting the resources into the 20" mod, if you truly intend to use this as a main desktop computer.  (Obviously if you already have a 17" dead iMac G4, its a different story).

Personally, it has become difficult for me to use LCDs under 19" as I've become so accustomed to larger displays.  The 20" iMac is a sizable display as is, but several factors actually make the screen bigger than most 20" displays.  For one, the aspect ratio is 16:10 not 16:9, for 20" this makes a substantial difference (1680x1050 vs 1600x900) in the overall size and pixel density.  Plus, the nature of the iMac G4 itself allows you to pull the display much closer to you than an ordinary LCD would sit.  Even still, to be a workstation, I feel multiple monitors are invaluable.  I got fortunate in "spare parts" that I was able to put the iMac G5 (native LCD, Apple Cinema Display's controller, inverter, and power source) together very quickly.  However, there are multiple ways to "resurrect" an iMac G5 as an external monitor depending on available parts.  The effect of having both together is great.  The iMac G5 is also quite ergonomic, in both its sliding and tilting.

While an All-In-One was the ultimate goal, by the time I figured out how to "modernize" the iMac with a Core 2 Duo Processor, Core 2 Duos were obsolete. With the mac mini also growing in length and depth, an all-in-one would need to be a hackintosh.  While the discussion regarding the price point of the mac mini is justified (depending on how you value aesthetics, form factor, and low power consumption), you can not call this generation underpowered.  I have been quite impressed, unless you are a gamer, there is not much you can't do with this machine.  (Im using the 2.7Ghz Dual Core i7 with discrete graphics.) For those waiting for the "X-Mac" this really might be it.

I originally concealed this in the inner part of the desk, but the I bought a great under desk mount with 4 front facing powered USB ports.

As I've mentioned the loss of the optical drive even as an option was unfortunate.  While both the G4 and G5 enclosures lend themselves to addition of an optical drive, its on the G4 where the drive actually contributes to the design.  While initially I was hoping to use bluray - Lion would not recognize the drive.  I ended up using an external DVD drive which I opened up and modified.

This is actually DC powered, so I used a power source from a broken internal drive enclosure.  I use the original iMac G4's AC plug, but split it, with one going to the cinema displays power brick and one going to the drive.  Thus, only one AC plug and no external power brick is required.

Rear Ports (USB Out, Drive Switch, AC Power)

The rear panel contains the original 3 pronged receptacle for AC power, an on/off switch for the drive, a USB out, the outgoing USB cable and HDMI cable.  The USB cable belongs to the cinema displays controller which then supplies 2 ports.  One is taken up by the drive internally, the other is on the back (hooked up to the camera here).  So, by having the drive plugged in, you essentially replace the used USB port.

Drive open

There is a quirk with the DVD drive.  When there is no media in the drive, the keyboard eject shortcuts do not work and you can not access the front button on the drive.  To eject the drive you have to open disk utility, click on the drive and press open.  Now by putting Disk Utility in the dock, opening the drive takes only 3 clicks, however, this is somewhat of a nuisance.  When media is in the drive this does not seem to be a problem.


SOLVED - thanks to fellow modder and iMac enthusiast Jean Luc, I now have an eject icon in the upper right corner, that allows me to easily eject and close the drive in the G4's dome.

This works flawlessly.  It eliminates a flaw of the mini and gives purpose to the base of the iMac G4.

Besides cleaning up a few of the rear ports, this iMac G4 mod is complete and perfect in this setup.  This is largely the same mod as before without the all in one.

Side/Rear iMac G5 (1st Generation) Mod

The iMac G5 chassis leaves plenty of room for further modification.  It is designed for speakers and its own drive.  Because I have an optical drive in the G4 and use the apple pro speakers, these are likely to be superfluous.  As of right now the Cinema Displays cable goes out where the power cable exited.  So the power brick is outside.  I may internalize this.  While I do like the ability to physically move the camera, I may consider obtaining an isight G5 and seeing if I can get an isight camera and convert it to USB.


UPDATED - with advise from Jean Luc and research I have realized that there is a considerable difference between the original iMac G5 (1st Generation)and the iSight iMac G5 (3rd Generation - much thinner, and with iSight camera/mic).  I am going to attempt to transfer the contents from this G5 to an empty chassis from an iSight G5.  I believe this will likely fit this mod better.  As I have stated much of the iMac G5's shell is currently wasted space, having a smaller, sleeker chassis would likely look better and save some desk space.  Although much tighter, the only contents that will need to fit are the Cinema Display's LCD controller and inverter .  In addition, as Jean Luc explains in the comments below, the iSight is simply a USB device.  With addition of either a USB adapter for the microphone, I can connect these to the Apple Cinema Display's USB ports.  As this leaves only 2 Firewire 400 ports, I would likely either hold off on adding the rear ports to see if my "thunderbolt dock" idea becomes feasible, or use a firewire to usb dock to add USB ports to the rear of the iMac G5.  The RAM access panel at the bottom may also let me bring back the Cinema Displays hardware touch power and brightness controls to the bottom of the display.

FURTHER UPDATED - I have indeed used JLs advise and the chassis of the iSight G5 complete with original microphone and iSight Camera.  Please see this post on the iMac G5 iSight for details.

At the very least I'm likely to add the Cinema Display's Firewire 400 and USB ports.  As I mentioned earlier, this monitor is hooked up using a mini display port via the thunderbolt port, I'd love to utilize this fact to make this a "dock".  Exactly as apple has done with its new Thunderbolt displays.  Thus, with one plug I could not only get the image to the G5s LCD but "transfer" the mac minis ports to the easily accessible rear panel of the G5.  This would allow for significant convenience.  I'm hoping such a dock may eventually become available or perhaps it could be taken from a broken thunderbolt display in the next year or so.

In general this is even beyond the setup that I envisioned as a best case scenario when I began this project.

Suggestions are appreciated.  And if there is interest I'd be happy to provide technical details.  Thank you for reading!

Optical Drives, Mac Minis, and Thunderbolt

Courtesy of apple.com

So the final part of my setup is "the actual computer".  I decided to go with the higher end non-server model.  I would have gone with the server for its quad core i7, but discrete graphics is quite important to me.  I have had some so-so experiences with onboard intel graphics in the past.  In terms of upgrades - I very much wanted a SSD, but for $600, it was not going to happen.  I have spoken to people who have changed or added drives to last years mini (same design) and while not simple it is doable.  So I went with the base 5400rpm 500GB drive knowing that eventually I'll likely add another drive or swap this out entirely.  I did decide to invest in the 2.7Ghz dual core i7 processor as this is something I won't be able to replace later and at $100 the cost wasn't ridiculous.

There was one "surprise" for me, I was not expecting the demise of the optical drive.  While this does cause me to alter my design, it really is not a big deal for me.  That said, I am somewhat disappointed in the decision.  The reason I say that is because it decreases the versatility of the machine.  Plenty of people viewed this as an ideal and elegant HTPC, many of those people have DVD collections, instead of an iTunes movie library.  For the Macbook Air - the initial decision to loose the optical drive allowed the chassis to become even thinner.  In the case of the mac mini there is an empty bay.  The design hasn't gotten smaller and unless you have two storage drives there is simply empty space.  Even if a drive wasn't included in the base model, an option for a Build to Order one would have been nice.  Optical media may not be the future but for many people it is the present and as small as it is, the mini is still a desktop computer.  Obviously, Apple can do what they want and as a huge media digital distributor they have a vested interest in seeing optical media disappear as soon as possible.  But, I thought they could have waited another generation as the people I know who waited for this machine as a living room computer have not decided to go digital, but have instead gone in a different direction.

This does open up some design potential for my setup which uses a converted iMac G4 and iMac G5:

While my initial design included a bluray drive in the base, I took it out as I thought it was redundant with the mini on the desk.  An internal drive was less complicated when there was a computer in base.  As this attached simply through an SATA + PWR connector to the motherboard.  While SATA to USB + Power brick adapters are available, I would like to keep the design as simple as possible.  Meaning I would prefer only one AC plug, no external power bricks and as few cables going between the mini and and the iMac G4 chassis as possible.

For there to be only "1 plug" I obviously have to split power off somewhere.  I can do this on the "AC side" before the power brick or on the "DC side" after the power brick.  I have an old 5.25" external drive enclosure that I have no further use for.  This includes a small power supply and onboard SATA to USB.

With some internal rearrangement I should be able to fit both the power supply as well as the drive.  Currently all that is in the base is the Cinema Displays LCD controller and Power Brick.  I am hoping to keep the power supplies at the top of the dome.  The drive in the middle and the controller on the underside of the drive.  Leaving the very bottom for some wire management.

Using the Cinema Display's on-board USB ports will allow me to connect the drive and replace the "used" USB port with one that will be on the back of the iMac G4s base.  In addition I will add either the rocker switch or a push button on/off to the back of the iMac G4 for the drive.  I do have the option of Firewire 400 ports but will probably not hook these up.  Although there is not currently any reliable support for it, I do have a full side 5.25" tray loading bluray drive which has already been modified to fit in the iMac, so I will probably be using this.

Courtesy of CNET

Another option is to use the iMac G5 or both.

PicoPSU by Mini-box.com

Of course, as I have previously noted, I have plenty of room in the iMac G5's chassis.  The way I felt this looked the best was to mimic the original look, whereby one cable comes out the back.  So the Cinema Display's Cable comes out the hole n the back, which I will eventually surround with white rubber to make it look as clean as possible.  As a result, the power brick is external.  To use an internal slim slot loading I need an SATA power source (12V), but the power coming in via the Cinema Display is DC at 24V.  In order to siphon off power I need a DC to DC voltage regulator or power supply.  I chose a picoPSU which can use 24V input.  I chose this because it was cheap, small, gives me lots of options, and I am familiar with it.

Using this and a SATA to USB I can again use the onboard USB slots of the cinema display.  And as I am already connecting the Cinema Displays cable to the computer, I may hook up the firewire 400 ports and connect them to the back of the monitor where they were designed to hook up to the iMac G5.

Back Panel Thunderbolt - Courtesy Apple.com

In my opinion one of the most interesting products Apple just launched was its new Thunderbolt display.  The idea that one cable (externally no different than the display cable) can turn the monitor into a "dock" is brilliant.  What would be ideal for my setup would be if they ever sold a separate "Thunderbolt dock".  A Thunderbolt cabe at one end with a mini display port, USB, firewire, ethernet, thunderbolt out (for daisy chaining) etc at the other end.  This would allow all sorts of devices/accessories to be stored in the iMac G4/G5 housing.  An example may be using Macbook Air with onboard Intel HD3000 graphics hooked up to a modified iMac G4 or G5.  But inside of the iMac enclosure is not just an LCD but a powerful PCI-Express graphics card hooked up via thunderbolt (I know it wouldn't be fully x16 - but it would still be very capable) as well as a 3TB HD array and Bluray drive that all becomes accessible as you hook one cable up to your laptop.  It really may make these mods more than just monitors.

20" iMac G4 Inverter Pinout (Not tested)

Based on the voltages from my current setup with the Apple Cinema Display as the power source.  You should be able to hook this up to a native working iMac G4 20" power source, but as I do not have a working one I can not confirm this.

iMac G4 20" Inverter Pinout

To be honest I am not sure exactly what the yellow wire does and I can not guarantee that there is not something else missing.  I believe its also involved in on/off control.  I am not sure about what resistor as I do not know the current, but it would be high - at least 1Kohm.

The TMDS to DVI for the ID Tech panel can be found here.  Again this is based on ID Techs own specifications, so I am very confident about in this pinout, but have not tested it myself.

If anyone does have a power source and gives this a shot please let me know the results.  Good luck.

20" LCDs, Signaling, Inverters, and Pinouts

After getting some questions, I realized that it isn't very clear on my blog what makes the 20" iMac G4 different from the 15 and 17" models.  Simply put the difference is the inverter and powering the backlights on a 20"LCD.

Monitor Components

I) Intro - LCDs

To explain just some basics about LCDs: (I am no expert so please forgive me if things are slightly wrong or grossly oversimplified).

Most monitors (that connect to an AC power source) contain the LCD itself and then two boards. (See image on the right)

1) Top of the image is the LCD controller board.  This is where DVI/VGA plugs in and gets converted to a signal type, usually LVDS.  The controller also connects to a power button and some other control buttons.  Thus, the board can adjust aspects of the image such as brightness, contrast, position etc.

2) Bottom of the image is the Power Source/Inverter.  AC Plugs in here and powers the backlights (connectors at the bottom).  The backlights traditionally CCFL lights (now more LED) allow you to see the displayed image.  The AC is also converted to DC and supplies power to the LCD controller and via the LCD controller the LCD panel itself.

JAE connectors

II) Signaling Types

LVDS (Low Voltage Differential Signaling) along with power (usually 5 - 12V) and ground wires go from the controller to the LCD via a multi cable connector - usually a JAE connector.

Every Apple Product involving an LCD that I have worked on so far works somewhat differently.  This includes all the iMac G4's, the 20" iMac G5, and the 20" aluminum Apple Cinema Display.

The major difference is that the Type of signaling used is TMDS (Transition Minimized Differential Signaling).  While I do use the term "TMDS to DVI conversion" in my blog, this is actually a misnomer as there is no real conversion.  TMDS is the type of signal that DVI and HDMI cables use.  Nothing gets converted, its just that the wires get arranged in the right sequence and POWER is added.  Inside the LCD casing itself there is a Texas Instruments chip that allows the monitor to utilize the TMDS signal.  Therefore, ALL of the LCDs in the above computers can be connected directly to any TMDS signal - meaning any source that sends a signal over a DVI or HDMI cable.

Panel Names: (May not be complete) - All TMDS compliant

iMac G4 17" - LG LM171W02(A4)

iMac G4 20" - IDTech M201Z2-M01

iMac G5 20" - LG LM201W01(A5)(K1, K2, or K3)

Aluminum Apple Cinema Display 20" - LG LM201W01(A6)(K1)

III) LCD Controllers

Inside the Cinema Display

DVI going directly to LCD

Even though all the data goes directly to the panel, there are still LCD controllers.  In the case of the iMac G4 and G5, the controller is in the motherboard.  There is no conversion of signal, but power to the panel and brightness is controllable.  There is an LCD controller in the cinema display.  The actual TMDS data cables go directly to the LCD from the DVI cable.  The ACD's LCD controller does add the power to the display and changes brightness, connects to a power button, and is also a USB/Firewire hub.

Again, for all these panels, you can connect DVI or HDMI wires directly to the LCD's JAE wires.  As long as you also supply power for the panel (12V for the 20" panels and Grounds) as well as forgo hardware control of brightness - you will produce an image.  But, you will not be able to see the image without backlights.

IV) Inverters

Like any monitor with CCFL backlights you need to AC power.  The iMacs do not need a power source because the computer itself already has one.  DC voltage goes to an inverter that turns the DC voltage into high AC voltage (>1.5 Kilovolts) allowing the bulbs to turn on.  The Cinema Display actually works the same way.   The external powerbrick is the power source, taking AC and putting out 24V DC.  So even with a working image you need an inverter to turn on the backlights to see it.

For the 15" iMac G4 other modders were able to figure out what to feed the inverter to get it to turn on.  They used an ATX power source.  I determined the 17" iMac inverter pinouts because I had a working inverter, power source, and although it froze with booting - motherboard.  So because there was an image I was able to determine what voltages went to what inverter cables to turn the backlights on.  I then used an AC to molex adapter (Gives 12V, 5V, and Ground), approximated the voltages (I didn't have a 3.3V line), and turned on the backlights.

So here is the problem with the iMac G4 20".  First, no other inverter which can power the backlights that I have found is thin enough to fit in the case.  Trust me I've tried a lot - See this post for details.  So while there was only 12V, 5V (3.3V recommended but not needed) for the 15" and 17", the 20" was not so simple.  Remember all these voltages are easily available from any ATX power supply.  The 20" inverter needs a 24V power line.  In addition, while I can identify the power lines, grounds, on/off, and dimmer of the other inverters, there was an extra wire with the 20" that I'm not really sure what it does.  So, you need a power source capable of 24V, 12V (to power the LCD panel), and 3.3V - any old ATX power supply will not do.  The native iMac G4 20", G5 20" or 20" ACD all have power supplies that do have a 24V output.  That was original reason i was using the Apple Cinema Display in the first place - I did not have a working iMac G4 20" power supply.  What complicated things further was although I had a general idea, I could not determine voltages from a multimeter, thus it was guess and check.  Unfortunately, when I burned out an inverter I realized that this method wasn't going to work.

V) Solutions

Using the controller of the Apple Cinema Display solves the problem.  The controller is really a series of resistors that takes the 24V DC and splits it up into the voltages needed to power the panel and the inverter.  Plus it adds on/off, brightness control, and a USB/Firewire hub.  But, this is essentially the same as the "TMDS to DVI conversion for the 20" that I posted here, as far as the TMDS data is concerned.  Using this controller simplifies and stabilizes the system very well.  This is obviously not the most cost efficient method.  However, buying a working 24V power source can be expensive as well, so if you need to buy one anyway, I would recommend going for a cinema display with a broken screen.

But for those of you that either have a working iMac G4 20" power supply or some other 24V source there is obviously a way to get it working.  Now that I actually have a set up that works, some may wonder if I can now determine what DC voltages are needed to "activate" the native inverter.  The answer is yes and I have already done so - I will post the inverter voltages in my next post.  Two things about this are unusual. For one, there is a yellow wire with an extremely low voltage, I believe its part of the on/off mechanism or backlight control.  I am not sure if there is something else that I am missing with this wire.  Second, I have given just the voltages, you will need a fairly high resistor for the yellow wire even if you connect it to the 3.3V, but I don't know the current of the power supply to calculate it.

Video of 20" iMac G4 All-In-One ECX Mod

Before I removed the contents of the base to convert this mod to an external monitor for the mac mini I shot a quick (and shaky - sorry) video demonstrating its use.  I have stored all the contents including the bluray drive and ports.  The new Quanmax ECX board is due out at the end of the month and if it is not cost prohibitive - it could quickly be reassembled.  I'm hoping that, for one - there are new mac minis and secondly that they do not disappoint.

 For those of you interested in doing this mod, but wanting an all-in-one - use an ECX board - trust me.  I spent hours trying to shoehorn a mini itx into this thing and have spoken to plenty of modders who have done the same.  I bought all right angle port connectors - tried all angles.  Eventually I'd get it to close, but then within a couple hours I had to reopen it for something. (Short out, wire hitting the fan etc.). The one person I know able to get it closed and working has to power down periodically as a result of heat issues.  The base is a very poorly vented thick metal cage.  There are a few slits at the bottom and holes at the top.  Apple designed this to be convection cooled.  When I had updated the inside RAM in an original iMac G4 I forgot to put thermal paste on the two heatpipes when I closed it back up and the iMac would not stay on for more than 2 minutes - that's how delicate the convection cooling system was.

Mini itx in bottom of dome

The unavoidable flaw with a mini itx board in this setup is that it has to sit at the bottom of the dome (its the only place it fits).  So everything is above it.  There is no way to fit a DVD/Bluray with a mini-itx as the RAM and heatsink come up way to high.  Despite removing this, at minimum you will have the hard drive (even a small one), a power supply (The ECX board connects from a 4pin to external power bricks), and lots of wires that will all occupy the area above mobo - obstructing what little airflow there is.  And its a long way up to those small ventilation holes at the top of the dome.

Native HDD and DVD vs. BLURAY and ECX Mobo

The ECX is 3.5" (the exact same size as the native hard drive).  You can easily put a SSD below it or at the bottom of the dome (mine has a CF slot), and it does not require a separate power supply.  Most importantly the ECX by virtue of its size can sit at the top of the dome with its fan right under the ventilation holes.  And to be honest it was still pretty hot!! But at least not dangerously so.  For those interested ECX boards come in many varieties.  Quanmax and Portwell are two of the bigger manufacturers.  I am waiting for the new Sandy Bridge line, but there is nothing wrong with some of the newer Atom boards. Lets face it - if you are doing a 15 or 17" mod its probably not going to be a gaming computer.  As a secondary computer, it would probably be more than adequate.

Photo courtesy of Electronista

In terms of opening a mac mini - I'm not sure - while its designed to be very low voltage it would have to sit at the bottom and therefore heat is likely to be an issue.  To be honest, I kind of consider this now a moot point.  The newer mini design is likely here for the foreseeable future and although thinner, its mainboard is now likely too big to fit into the dome.  The previous generation core 2 duo will fit, but without a clear upgrade route I wouldn't risk taking it apart.

Question, Comments, and Advise always appreciated!

My Dream Setup - iMac G4 and G5 - Dual Monitors

The iMac G4 "mac mini monitor"

Although this has been a great hobby for me, my goal has always been to produce a computer and setup which allows me to use the form factor of the iMac G4 with modern hardware and the Mac OS.  As you can see from my summary, most of my mods - besides the black iMac/VESA - have been disassembled for parts as I feel that the mods have gotten better and I simply don't have use for that many iMac G4 hacks.  The fact that I have completed a 20" all-in-one iMac G4 complete with ports and a blu-ray drive using the ECX core 2 duo board shows me that this mod is doable. The only negative is problems with snow leopard (and presumably Lion) with this board.  However, there should be no compatibility problems with the new Sandy Bridge KEEX-6100. Still, I have expressed my reservations with hackintoshes in the past and I would prefer a true mac.  So while I have been using my touchscreen iMac/Cinema Display mod with my old mac mini, I have really come to prefer the appearance of my newer mod, the native iMac G4 all-in-one mod.  So after filming a video of the all-in-one mod and much deliberation, I decided to disassemble this mod and "switch" this mod with the apple cinema display one.  Thus, I will get the benefit of a brand new/white exterior and the native housing which makes this completely indistinguishable from the original iMac G4.  I will however loose the touchscreen.  I simply felt that this came closer to what I originally set out to do.  For myself I do not mind the small footprint of the mac mini being on the desk as well.  Plus, this leaves open other possibilities such as using it as a desktop monitor for my Macbook.

Two Ports: DVI and Power

I did decide to make one additional switch.  Although the mod works fine with the original iMac G4's LCD - the apple cinema display's LCD has a better contrast ratio, viewing angle, brightness, and response time.  I had an extra apple cinema  LCD (which was intended for the mod detailed later in this post that I ended up not needing).  So I replaced the iMac G4's LCD with the Cinema Display's.  Here you can see photos of the new iMac G4 hooked up to the mac mini and apple pro speakers via the iFire adapter.

From the back

 I left out the bluray drive (as Mac does not yet support it), but now have plenty of room for the power brick which is now included internally.  So only a DVI out and C14 Plug is required on the back.

iMac G5 with Cinema Display Cable

My ideal setup has multiple monitors.  Unless I have a 27" screen - I find having the extra screen real estate important for multitasking.  At first I considered two iMac G4s but thought that may look odd.  So I decided to add my second favorite iMac design of all time - the iMac G5.  I obtained a broken 20" iMac G5 in good cosmetic condition and removed all but the lcd itself.  I had an extra apple cinema display with a broken screen - I put the cinema displays components around the native iMac G5's lcd (which luckily still worked) and I now have an external monitor in a G5 shell.  For now I just wired the cinema displays cable out the back where the C14 plug used to be.  There are still some issues to work out such as the monitor now being very light.  Also, the screws in the bottom no longer fasten into anything.  And, I do plan on wiring the 2 USB and Firewire 400 inputs of the Apple Cinema Display to make them accessable on the rear panel of the G5.  I know I did not go into detail on this mod - as there really isn't much to it.  Just know that the native iMac G5 panel works with a cinema displays controller board.  If anyone is interested in this, please let me know and I will add a step by step and parts list.  And if you are wondering why I didn't use the TMDS to DVI hack, its because I would still have to power the iMac G5's inverter which also requires a 24V line.  Sure, the iMac G5's power supply could be altered, however, the power supply on this was broken and I had the cinema display components.

On the 20" iMac G4

Unfortunately, my mac mini does not support dual monitors (the current one does).  I am hopeful of a new Sandy Bridge mac mini which will be the centerpiece of this setup.
So first the iMac G4 connected to the mini.

On the 20" iMac G5

Then the iMac G5 connected.  And hopefully in July...Both!










As always comments, questions, and suggestions are appreciated.  Thanks for reading!