Portable News
 PB Zone

 iMac News
 Daily iMac

 Forum
 MacDebate.com

 Gaming News
 Mac 3D Dot Com

 Mac OS X
 X Appeal

 
 Quotes

 
 

Paul Cesarini

That's the question I've been wondering since Steve Jobs introduced the new iBooks last week. The short answer is no, monitor-spanning isn't possible. The likely business-related reason is that Apple doesn't want too much feature parity between the iBook and PowerBook G4. Too much feature parity may well cannibalize sales of the PowerBook G4. As this has been a huge money-maker since it was introduced, Apple hardly wants to shoot itself in the foot. So again, the short answer is monitor spanning in not possible.

However, the technical reason begs a few questions: Is monitor spanning not possible because the Rage Mobility chip in the new iBooks is different from the one used in the PowerBooks? Does the new Pangea I/O controller have anything do to with this? That is, are we talking about a hardware limitation? Or, is monitor spanning somehow disabled via software? In either case, can monitor spanning be re-enabled by some sort of hardware and/or software hack?

Of course, even if it could be re-enabled, any hardware hack would make your warranty nosedive faster than a U.S. spy plane over Hainan Island. Even a software-only hack could theoretically damage either the display or the graphics processor. So be warned: don't even think of getting out your soldering iron and screwdriver unless you really know what you're doing.

That being said, the purpose of this article is to disseminate current, publically-available information on the video capabilities of the new iBooks, side-by-side with that of the PowerBook G4s. The goal is that someone will look into this issue a bit more deeply, and perhaps provide an answer. I would, but my programming and component-level technical skills rank right up there with my keen understanding of the opposite gender: ethereal, at best.

PowerBook G4*:

Card Name:	ATIRageM3p12A
Card Model:	-1
Card ROM#:	Not available
Card Revision:	2

* Information taken from stock PowerBook G4 / 500 configuration.

"The graphics controller IC is an ATI RAGE Mobility 128. Along with 8 MB of on-chip SDRAM, the graphics IC contains 2D and 3D acceleration engines, front-end and back-end scalers, a CRT controller, and an AGP 2X bus interface with bus master capability.

The interface between the graphics IC and the rest of the system is an AGP 2X (accelerated graphics port, double speed) bus on the Uni-N IC. To give the graphics IC fast access to system memory, the AGP bus has separate address and data lines and supports deeply pipelined read and write operations. The AGP bus has 32 data lines and a clock speed of 66 MHz. The graphics IC uses a graphics address remapping table (GART) to translate AGP logical addresses into physical addresses. The graphics driver software can allocate memory in both the on-chip SDRAM and the main memory.

The graphics IC supports the built-in flat-panel display and an external monitor. The external monitor can either mirror the built-in display or show additional desktop space (dual-display mode).

An external monitor or projection device connected to the computer can increase the amount of visible desktop space. This way of using an external monitor is called dual display to distinguish it from mirror mode, which shows the same information on both the external display and the built-in display."

PowerBook G4*

Monitor Connector Signal Pins / Graphics Block Diagram * Source: PowerBook G4 Developer Note

Signals on the Monitor Connector Pin Signal name Description 1 RED Red video signal 2 GREEN Green video signal 3 BLUE Blue video signal 4 MONID(0) Monitor ID signal 0 5 GND DDC return 6, 7, 8 AGND_VID Analog video ground 9 +5V_IO 5 V power 10 GND HSYNC and VSYNC ground 11 VGA_ID VGA ID signal 12 MONID(2) Monitor ID signal 2 13 HSYNC Horizontal synchronization signal 14 VSYNC Vertical synchronization signal 15 MONID(1) Monitor ID signal 1

iBook (Dual USB)*:

Card Name:	ATIRageM3p29s
Card Model:	ATI RageM3
Card ROM#:	113-XXXXX-125
Card Revision:	2

* Information excerpted from the MacProf site (Italian).

"The combined audio and video output jack (A/V/ jack) on the iBook computer provides a composite video signal for a TV monitor. The video output mirrors the flat panel display: internal and external video share the same buffer, and the hardware sends the image to both displays.

The iBook computer has an output port for connecting an RGB video monitor. The computer detects when a monitor is plugged in and configures the display appropriately.

The RGB display operates in mirror mode, which duplicates the display on the internal flat panel. Display sizes supported are 640 by 480, 800 by 600, and 1024 by 768 pixels.

The connector is a 14-pin rectangular connector, Hosiden TCX3143. The RGB connector is compliant with the VESA specification (DDC version 3)."

iBook (Dual USB)*
Monitor Connector Signal Pins / Graphics Block Diagram * Source: iBook Developer Note	Signals on the RGB Connector 1 Ground 2 VSync 3 HSync 4 Red return 5 Red video 6 Green return 7 Green video 8 +5 Volts 9 Blue video 10 DDC data 11 DDC clock 12 n.c. 13 /Cable detect 14 Blue return

The Apple System Profiler readings from the PowerBook G4 and the iBook (Dual USB) are, I believe, interesting. Is the ATIRageM3p12A card in the PowerBook G4 the same as the ATIRageM3p29s card in the iBook? Or, as the names seem to imply, are they different versions of the same Rage Mobility card? The ATi site doesn't provide much additional information.

After doing some digging, I found out the Hosiden TCX3143 reference is likely from a company called Hosiden Corporation, based out of Yao City, Japan. Their web site seems to indicate that they do, in fact, make components for laptops. However, there doesn't appear to be any info on their site about the RGB connector, or the "TCX3143" model number. The same applies for VESA site, which I thought would be a sure-fire source of information.

The lack of monitor-spanning in the new iBooks certainly isn't a deal-breaker for most people -- especially considering the reasonable price points for each configuration. Still, monitor-spanning is a useful feature many of us take for granted in laptops. Apple has, over the years, repeatedly offered this feature then taken it away again. My first PowerBook, a trusty PowerBook 540c, had this feature, while my Wallstreet (G3/300) inexplicably didn't. Go figure.

So, where does this information leave me? Unfortunately, exactly where I started. I'm still not able to answer whether or not monitor-spanning is disabled via hardware or software, nor do I know if a hack of some sort is probable, or even possible. If anyone has any suggestions, by all means let me know.