The Mini DisplayPort connector can turn a 27" iMac into an expensive monitor

I didn’t intend to buy a new iMac. I was happy with my Mac Mini desktop system and my MacBook Pro was a fine portable (now that the video has been repaired). I simply wanted more display real estate so I could do some video editing. But my shopping trip took a detour at the Apple store: The 27″ iMac is simply the best computer monitor you can buy, and it happens to have a great computer embedded in it too! The gorgeous LED IPS panel and massive 2560 x 1440 resolution really shines in intensive applications.

There is another secret lurking inside, though: The Mini DisplayPort connector on the back is bi-directional, so you can connect another computer, turning that new 27″ iMac into a gorgeous monitor! I was eager to try this out, and sure enough my 2009 Mac Mini had no trouble taking over the iMac’s display using a $30 Belkin cable. But actually using the iMac in this configuration has not been pleasant.

The Basics

First, only “late 2009″ 27″ iMacs have this display input capability. Although the ports on the back of the 21.5″ iMac and others look identical, none can do this trick.

Get your hands on a 27″ iMac, a Mini DisplayPort cable (I used this $30 Belkin cable), and a recent Mac Mini, MacBook, or other computer with a Mini DisplayPort video output. Plug one end into the iMac and the other into your other Mac. As soon as the two Macs are running, the display will blank out and switch from the iMac to the external one.

You can switch inputs by pressing Command-BrightnessUp (usually Command-F2 or Command-Fn-F2) on the iMac’s keyboard. It will also automatically switch when it detects a signal, such as when a computer is connected or wakes up from sleep.

While the external source is displayed, the iMac will ignore most keyboard and mouse movements. Some special function key commands appear to continue working, however, including brightness (F1/F2), rewind (F7), play/pause (F8), fast forward (F9), and mute/volume (F10/F11/F12).

The Limitations

Sound good? Well, there are some serious limitations that make this not so great in practice.

1. I can’t get any USB keyboard to trigger the display switch no matter what I try. Only the original Apple BlueTooth keyboard that came with the iMac will trigger a switch. This annoys me, since I’m a dedicated IBM Model M user…
2. There is no KVM capability in OS X, so the keyboard and mouse are useless when you connect an external computer. I use an IOGear USB KVM and was able to get this working with my Mac Mini and iMac, but switching required the otherwise unused BlueTooth keyboard (see above).
3. The iMac has to be on and running OS X for the Mini DisplayPort input to function.
4. Switching sources takes a second or two, and the iMac switches displays whenever the connected computer wakes from sleep. This leads to some surprising work pauses if you leave it connected.
5. Only native DisplayPort video is usable. Although there are many cheap Mini DisplayPort adapters, these are normally for output only and will not work. So computers with VGA, DVI, or HDMI ports won’t work. without a converter.

I tried all sorts of tricks to send the proper key sequence from my USB keyboards and using AppleScript, but nothing worked. I’d love for Apple to deliver a KVM solution in OS X, but barring that an enterprising programmer ought to be able to figure out a software solution.

Can It Be Used With Other Computers?

The short and easy answer is no, the iMac’s Mini DisplayPort input is very unlikely to work with anything but a Mac, since most non-Macs don’t use DisplayPort. And since DisplayPort is a computer (rather than entertainment) standard, it’s unlikely that your Blu-Ray player, game machine, or DVR will work either.

The medium answer is yes, it might very well work just fine with some PCs equipped with a DisplayPort video card.

The longer answer is yes, a variety of companies are working on adapters to allow other devices to use the iMac’s display. Apogee has promised a special converter box just for this exact purpose, and folks have had varying success with the Gefen and Atlona converters.

The very long answer is that you can force just about anything to work with the iMac’s Mini DisplayPort input but it’ll be very hard and probably not worth it. There are three things to consider when trying to send video from one device to another:

1. The physical/electrical connection must be compatible. The iMac only accepts Mini DisplayPort cables, so any connected device must terminate with a male Mini DisplayPort connector. Most basic (read cheap) DVI or HDMI adapters can not convert formats, and merely connect appropriate pins from one format to another. There are plenty of cable and adapter options for regular DisplayPort, however. But DisplayPort 1.1 fiber optic cables are right out.
2. The data format (including DRM) must be compatible. Simply using a DVI-to-Mini DisplayPort adapter is insufficient. The DVI device will send DVI signals that the iMac won’t be able to interpret, or they might not be connected at all. Even if the data format is converted correctly, it appears that the iMac does not support HDCP input, although HDCP is enforced for signals output to HDTVs. This means that a DVI Blu-Ray player might not display correctly on the iMac even if the DVI signal is correctly converted!
3. Display resolution is less of a concern, but must be considered as well. My iMac was happy with a variety of input resolutions from my Mac Mini, but the native 2650×1440 resolution is way beyond the DVI spec. So full resolution will require a dual-link DVI connection (expensive and rare) or a scaler (even more expensive).

What does this mean? Here’s the answer for various devices:

1. Apple computers with Mini DisplayPort connectors just need a cable, including the 2009 MacBook, MacBook Pro, Mac Mini, and iMac.
2. Other computers might work, provided they have MiniDisplayPort or plain large DisplayPort, though the latter requires a physical adapter.
3. Computers with DVI connectors (including older Macs) will probably need an expensive adapter like the Gefen, Atlona, or Apogee boxes and won’t be able to use the full resolution of the iMac without an expensive scaler box like this one from Atlona. We’re talking $100 to $500 to get things connected, and it might not work.
4. Entertainment devices like Blu-Ray players, Xboxes, and PlayStations likely require HDCP enforcement so they probably won’t work without some special anti-DRM voodoo. This is exactly what Apogee is talking about delivering, but I’ll believe it when I see it. And it’ll likely cost at least $200. Note that this is spelled explicitly out in the DisplayPort FAQ!

Conclusion

Finally there is the issue of sound and control. The iMac’s Mini DisplayPort input only supports video, so audio and USB connectivity requires an alternative path. You can use a KVM like my IOGear to switch your keyboard and mouse, but no audio will be sent. Probably the best compromise would be to use external speakers for both the iMac and connected device.

So there you have it. The iMac’s awesome display can be used by external devices. But it’s not really satisfying to use without some extra devices: A KVM and speakers at least, and some expensive video voodoo at most. Sorry to ruin your day!

© sfoskett for Stephen Foskett, Pack Rat, 2010. | Turn Your 27″ iMac Into An Awesome Monitor
This post was categorized as Apple, Personal. Each of my categories has its own feed if you'd like to filter out or focus on posts like this.

After a very, very long wait, Apple has finally updated the Mac Mini, their entry-level “bridge” Mac. It’s amazing that, after 19 months without an update, Apple’s new Mini looks exactly the same as the old Mini. But what’s under the hood matters, and Apple delivered a mixed bag there. The new Mini is an excellent home server, which is how mine will be used, but some poor choices limit its abilities out of the box.

You might also be interested in my initial Mac Mini review, or my post on upgrading the RAM and hard disk drive in my Mac Mini!

Out With the Old

Apple completely redesigned the innards of the Mini for 2009. It has always been a laptop in a box, so we were not surprised to see the updated MacBook’s specs duplicated here. The Mini includes that machine’s efficient and current Intel Core 2 Duo mobile CPUs, Nvidia chipset and graphics, 1066 MHz RAM, 802.11n and gigabit Ethernet networking, DVD SuperDrive, and 2.5″ hard drive.

A few welcome additions were made relative to the MacBook’s specs. The new Mini features five USB ports. It also brings joy to the hearts of the Apple faithful in the form of a FireWire port, albeit sporting the square 9-pin S800 socket rather than the old familiar 6-pin 400 spec. But the most interesting addition on the little Apple desktop is its two independent video ports: A Mini-DVI and a Mini DisplayPort. Each of these additions squarely focuses the Mac Mini at the desktop market, and each is welcome.

USB Madness

When the array of five USB ports was spotted in pre-release spy photos, Mac fans went nuts. Why would the new Mini add yet another port? And who needs five USB ports anyway? I, for one, was very glad to see this change. I’ve lamented the reduction in the number of USB ports found in laptops lately, and I think most end users would agree that more USB ports are needed. Witness two consumer phenomena to support this proliferation of USB ports:

1. One of the hottest-selling peripherals for the old Mac Mini was the Mini-shaped USB hub, and many of the other accessories targeted at the Mini included built-in hubs
2. Despite Seagate’s sagging numbers, USB hard drives continue selling like hotcakes, with an insider recently telling me that they’ve reached a 2:1 attach rate (meaning most computers have two of them!)

A disturbing trend in parallel with the disappearance of USB ports is the hobbling of those that remain. My MacBook Pro has just two ports and both are limited: One is low on electrical power and the other is shared with internal peripherals.

I assumed that the Mini merely included an internal hub, limiting the value of those five ports. I am pleased to report that this is not the case! The Mini actually has four separate internal USB busses and the five ports are spread among three of these:

So if you’re adding high(er)-performance devices to your New Mini, let me suggest this strategy:

1. Connect your most-important device to port 2 and it will have a bus all to itself (except when you use an IR remote, which isn’t often)
2. If you have only one other high-performance USB device, connect it to port 1 or 5 and connect your keyboard and mouse to ports 3 and 4, or vice-versa
3. If you have two more high-performance USB devices, don’t connect them to ports 1 and 5 or ports 3 and 4 – spread them out on 1 and 3 or 4 and 5!

The new Mac Mini's five USB ports share three USB busses

Or just use the handy FireWire port and grin smugly as only a Mac user can!

Square Pegs

We’ve heard a hundred times that the Mac Mini was designed to a philosophy of “bring your own keyboard, mouse, and display”. In other words, it’s optimized for what people already have rather than being bundled with a keyboard, mouse, and display like the iMac or forcing people to buy all new peripherals. But Apple’s relentless push to move their hardware platform forward has gotten in the way of this goal when it comes to the new Mini.

Although the inclusion of a FireWire port alongside the multitude of standard USB ports is welcome, Apple chose to use the 9-pin S800 port style rather than the more-familiar 6-pin port. FireWire peripherals aren’t common as it is, and S800 devices and cables are far less familiar. Although it is backward-compatible, thus the “bilingual” name often used by Apple, the much-faster S800 port requires the purchase of adapter cables to use older 400 Mb FireWire devices. Although I’m a storage geek and do own a few FireWire peripherals, none are compatible with the port on my new Mini. I have a “bilingual cable” in the mail to me as we speak, and there is a port adapter dongle, but this port stands in the way of the “bring your own” ethos.

The same can be said of Apple’s choice of video ports. It’s nice that Apple’s Mini DisplayPort is offered royalty-free, but this hasn’t made adapters any more common. Their VGA and DVI adapters are priced at $29 each, and third-party cables haven’t appeared yet, though Monoprice promises them this month. So one of the two video ports is of limited use, unless you dropped over $800 on the gorgeous Apple 24-inch LED Cinema Display. Let’s not even mention the troublesome $99 dual DVI adapter!

Then there’s the Mini-DVI port. Apple bundles a Mini-DVI to DVI-I adapter with the Mac Mini, so those of you who own a DVI monitor (and cable!) are all set. But this adapter lacks the VGA pins, so you can’t use a DVI to VGA adapter to hook up to your older VGA monitor or KVM. For that, you need to order a special Mini-DVI to VGA adapter (also in the mail).

So let’s get this straight: If you want to actually hook your pre-existing peripherals to the new Mac Mini, you had better hope they’re USB or DVI-I. Otherwise, you’re looking at spending $20 to $30 each for FireWire, Mini-DVI, and Mini DisplayPort adapters. The lack of a VGA solution is especially annoying, since it would have been simple for Apple just to include the VGA pins in their Mini-DVI adapter, allowing folks to use the DVI-to-VGA adapter they probably already own.

Inner Weakness

Although the new Mini is solidly engineered and built, Apple made two major sacrifices in internal specs in the interests of profit margins: The base Mini ships with too little RAM and a too-slow and too-small internal hard drive. I knew this going in, and was happy to buy the base model anyway, since I intended to upgrade it rather than spend $200 extra for a little more RAM and drive space or wait for a build-to-order custom Mini.

There is simply no excuse for Apple to ship the base mini with 1 GB of RAM. OS X Leopard is a full-featured 64-bit operating system, and 1 GB is too little to do much of anything with these days. RAM prices keep falling fast, so even the fancy DDR3-8500 SO-DIMMs used by the Mini cost just a few dollars. At least the company used a single 1 GB stick instead of two useless 512 MB units like the old Mini! I was lucky enough to find a fellow buyer who upgraded his RAM and is sending me his leftovers, but I may spend $50 in the next few months for a matched pair of 2 GB sticks.

Then there is the hard drive. The Mac Mini uses Hitachi’s base-model TravelStar 5K320 (HTS543212L9SA02) drive unit, easily the slowest hard drive I’ve used recently. It’s limited to 1.5 Gb SATA, and its single platter may help in the power and heat department but it gives a poor performance show. Xbench (not the best measure to be sure) shows this little drive  trailing the 120 GB Fujitsu MH2120BH drive that came in my (late 2007) MacBook Pro by about 30%, and almost 50% slower than the 320 GB Western Digital Scorpio Blue WD3200BEVT that I now use! Note that Apple apparently uses larger-capacity versions of this same drive in the bigger Minis and MacBooks. I wonder if the performance is any better?

The Mac Mini's internal 120 GB Hitachi hard disk drive lags its contemporaries and drags overall system performance way down, especially with just 1 GB of RAM

Although I was surprised by just how slow the hard drive was, especially when the limited RAM leads to swapping, I always planned to upgrade both. As I mentioned, there’s a second 1 GB stick on the way, and I ordered a blazing 320 GB 7200 rpm Hitachi TravelStar 7K320 at ZipZoomFly for $59 (after rebate). These should turn the Mini’s performance around!

Despite the shortcomings of the base Mac Mini, I would not recommend buying the upscale or build-to-order models if you’re open to upgrading it on your own. You can upgrade a Mini to 2 GB and 320 GB/7200 rpm for under $100 instead of spending $200 from Apple for the same RAM and a slower drive. However, if you’re hesitant to open the case, do not buy the base Mac Mini! Get at least the 2 GB model from Apple – 1 GB just isn’t enough!

I’ll be documenting my evolving home server environment, based around this little Mac, here on the site. Subscribe to my Apple feed (or stick with Everything) to keep up to date!

Note: Some of these links include affiliate codes that help pay for this blog. For example, buying an Amazon Kindle with this link sends a few bucks my way! But I don't write this blog to make money, and am happy to link to sites and stores that don't pay anything. I like Amazon and buy tons from them, but you're free to buy whatever and wherever you want.

© sfoskett for Stephen Foskett, Pack Rat, 2009. | New Mac Mini Is A Diamond In The Rough
This post was categorized as Apple, Everything, Terabyte home. Each of my categories has its own feed if you'd like to filter out or focus on posts like this.

I just solved the problem.  The old Apple Extended Keyboard, as revered by Apple fans as my IBM Model M, continued the function key mapping past F12, adding F13, F14, and F15 where Print Screen, Scroll Lock, and Pause/Break is on an IBM 101-key layout.  Then they mapped F14 and F15 to dim and brighten the screen, respectively.  See the problem?  Yeah, the IOGear hotkey is “dim dim”!

This post is part of my series focused on PC/Mac Integration.

• Vista, OS X Boot Time Compared
• Quick and Easy Bluetooth Sharing Between PC and Mac
• Yes, FireWire is Faster Than USB
• How to Keep an IOGear KVM from Dimming Your Mac's Screen
• Command and Control: The Clash of Keyboards

It turns out that this is easy to fix.  Leopard’s Keyboard & Mouse Preferences panel includes a tab to remap Keyboard Shortcuts.  Down at the bottom of the list is “Display”.  Expand it and you’ll see the two mappings in question – just un-check them and you’re good to go!

While you’re there, marvel at how none of the other function key shortcuts match up to their functions on the pre-2008 MacBook uses!  It’s a really bizarre oversight on the part of Apple to map bright/dim to F14/F15 and to F1/F2 on the same computer at the same time, depending if you’re using the built-in keyboard or not!  Apparently, the company shifted all the mappings around for the late 2007 desktop and early 2008 portables, too.

By the way, about that KVM – it’s pretty good, especially for the money.  I previously used a GCS62, which is a PS/2 in and out model with no audio, but the GCS632U is more suited to weirdos like me that like to use a PS/2 keyboard and mouse with a modern computer.  It takes PS/2 in but sends USB out to the connected computers, and includes audio, too.  It’s rock-solid, unlike the Belkin Flip I tried before, but I do wish the audio cable wasn’t captive to the video like it is – it’s just not long enough for the Mac.

Note: Some of these links include affiliate codes that help pay for this blog. For example, buying an Amazon Kindle with this link sends a few bucks my way! But I don't write this blog to make money, and am happy to link to sites and stores that don't pay anything. I like Amazon and buy tons from them, but you're free to buy whatever and wherever you want.

© sfoskett for Stephen Foskett, Pack Rat, 2008. | How to Keep an IOGear KVM from Dimming Your Mac’s Screen
This post was categorized as Apple, Computer History, Terabyte home. Each of my categories has its own feed if you'd like to filter out or focus on posts like this.

This post is part of my series focused on PC/Mac Integration.

• Vista, OS X Boot Time Compared
• Quick and Easy Bluetooth Sharing Between PC and Mac
• Yes, FireWire is Faster Than USB
• How to Keep an IOGear KVM from Dimming Your Mac's Screen
• Command and Control: The Clash of Keyboards

In this era of switchers, Boot Camp, KVM, USB, and virtualization, the question of how to deal with computer keyboard irregularities has become all the more important.  One of the most critical usability factors in cross-platform typing is the question of what to do about the so-called modifier keys: Control, Command, Alt, and the like.  See, each platform has its own key combinations for GUI shortcuts and common operations like copy and paste.  And although most are similar, they are different enough to frustrate even the expert user.

The Alt and Control keys found on most PC keyboards date from the first PCs, with so-called Windows and Menu keys introduced in 1995 and Fn or Function modifier keys found on laptops both before and after.  Combined with the Shift key (which pre-dated the personal computer) these are the most common modifier keys used today.

Most Windows commands use some combination of Ctrl, Alt, and Shift but the mapping is haphazard at best.  Generally, Alt-combinations control the GUI (switching windows and selecting menus) while Ctrl-combinations perform actions (copy and paste) but this is not always the case.  However, even though variations abound, the standard 101-key IBM layout dating from 1986 (shown at right on a 1987 IBM Model M) has dominated.  This places two “Ctrl” keys at the outermost position of the bottom row of keys with two “Alt” keys flanking the space bar.  The Windows, Menu, and (on notebooks) Fn keys are squeezed in between Ctrl and Alt.

The situation is quite different on the Macintosh.   Hardware-wise, the Mac inherited the Command (“open apple”/”cloverleaf” ⌘) and Option keys found on the Apple IIe of 1982, and added a Control key with the Mac II and SE to enable business-friendly terminal emulation capabilities.  As seen in the keyboard at right from my Mac SE, the Control key, as on the PC XT, occupies the space now associated with Caps Lock at left in the third row, while the Option and to-be-named Command key (with the Apple outline) sit roughly where the Windows and Alt keys would eventually live.

The popular Apple Extended Keyboard swapped Caps Lock and Control, settling the key layout of the Macintosh that has lasted through today, and added “Alt” to the Option key, clarifying its purpose.  In 2007, Mac fans were thrown into a frenzy as Apple made one more change, removing the Apple from the Command key and (finally) adding the word, “Command”, in its place.

If you’re a geek like me, you will find the history of these keys to be an interesting aside.  Wanting to add more functionality to their (integrated) keyboards, most early personal computer makers looked for ways of adding modifier keys without “breaking” existing programs, which were hard-coded for earlier layouts.  Most manufacturers settled on the so-called “Bucky bit” strategy, adding keys that modified the binary ASCII code from other keys. Alt set the eighth bit to 1, turning H (01001000) into 11001000, which could be a non-printable control character or one from another character set.  Similarly, Ctrl zeroed out the sixth and seventh places, turning both H and h (01101000) into backspace (00001000).  Apple took a different tack, literally wiring the open and closed apple keys to the joystick buttons on the Apple II.  Of course, nowadays keyboards merely send appropriate ASCII signals using a microcontroller, but these ingenious approaches certainly showed creativity!

This brings us to today.  Although both the PC and Mac feature a key called Control on the left, the Mac places Alt/Option next, followed by Command.  On the PC, the center spot is taken by the Windows key and the Alt is on the right.

This mapping problem is compounded by the fact that these keys do different things.  Command on the Mac takes on the GUI and action duties from both Control and Alt on the PC.  Alt and Ctrl stay true to their original uses, modifying the result of other keypresses and sending control codes, respectively.  None of this was much of an issue in the days of incompatible keyboard protocols, but today’s USB devices can be used with either platform, and virtualization and remote control have made rapid switching much more common.

Consider my case:  I use an IOGear USB KVM switch to control both my Mac and PC from a single keyboard (that ancient IBM) and mouse, as well as to output audio and video to a single LCD monitor.  I find myself switching rapidly between Vista on the PC, OS X on the Mac, and Vista in VMware Fusion, throughout the day.  And when I unplug the Mac and set it on my lap (in “Better Energy Saver” mode to keep from burning myself), I am suddenly using a Mac keyboard for OS X and Vista as well.  So sometimes the key combination for “copy” uses the key all the way to the left and sometimes it uses the one closest to the space bar, and this variation does not necessarily follow the OS I’m currently using or the keyboard I’m currently typing on.

OS X thoughtfully allows you to change the mapping of Control, Option, and Command in the Keyboard and Mouse preferences panel, and even lets you set different customization for different keyboards.  Lots of ex-Windows users use this to swap Command and Control with Control and Windows on a Windows keyboard, which harmonizes many familiar DOS/Windows command shortcuts.  And if you’re as insane as some Apple fans users, you could also use this panel to move Caps Lock and Option back to their original locations.

But is it a good idea to mess with the keyboard settings like this?  I think not.  Eventually you will need to use a “correct” keyboard, whether you are using a Windows or OS X computer, and crutches like this just serve to frustrate your efforts to acclimatize.  I think it’s best to simply live with it – to get used to using the right key combinations, no matter which input device or operating system one is using.

Of course, there’s one more problem for me.  See that keyboard layout up at the top?  My primary keyboard is, as I’ve mentioned, a 1987 IBM Model M.  Despite possibly being the best keyboard ever made, it is a 101-key model, not the more modern 104-key Windows unit.  I’ve gotten used to using Ctrl-Esc for the Windows key, and even Shift-F10 for the menu.  But I’m having a real problem with OS X because I simply do not have a Command key, and no amount of “getting used to it” will change this fact.  So for now I had to remap Control to Command, and I will have to live without a Control key in OS X.  Anyone have a better idea?

Note: Some of these links include affiliate codes that help pay for this blog. For example, buying an Amazon Kindle with this link sends a few bucks my way! But I don't write this blog to make money, and am happy to link to sites and stores that don't pay anything. I like Amazon and buy tons from them, but you're free to buy whatever and wherever you want.

© sfoskett for Stephen Foskett, Pack Rat, 2008. | Command and Control: The Clash of Keyboards
This post was categorized as Apple, Computer History, Terabyte home. Each of my categories has its own feed if you'd like to filter out or focus on posts like this.