Apple Mac iMac G5/2.0 20-Inch (ALS)

The latest iMac–the third incarnation, if you’re keeping track–is the natural evolution of a computer that keeps getting slimmer and slimmer. The first iMac was an all-in-one egg-shaped system, and the second looked more like a desk lamp than a PC, with the CPU hidden in its half-dome base. In this third design, the computer has seemingly disappeared altogether, and we’re left with a floating flat-panel screen. Some things haven’t changed, though: the Apple iMac G5 is still more about style than substance (it’s a good performer but not an excellent one), and it’s still not very expandable.

Like their predecessors, the “chassis” of the “Ambient Light Sensor” iMac G5 models rest upon an aluminum stand with an adjustable hinge, and it supports the “Video Electronics Standards Association (VESA) mounting interface standard” which makes it easy to mount the system directly on a kiosk, wall, or articulating arm. Additionally, as the name implies, all “Ambient Light Sensor” models have a sensor under the edge of the display that dims the sleep indicator light when the room is dark — a nice touch for a system setup in a bedroom.

The iMac G5/2.0 20-Inch (ALS) features a 2.0 GHz PowerPC 970 (G5) processor with an optimized AltiVec “Velocity Engine” vector processing unit and a 512k on-chip level 2 cache, 512 MB of 400 MHz PC3200 DDR SDRAM, a 250 GB (7200 RPM) Serial ATA hard drive, a vertically-mounted slot-loading 8X DVD-R/CD-RW “SuperDrive”, ATI Radeon 9600 graphics with 128 MB of DDR SDRAM (AGP 8X), and built-in stereo speakers underneath the 20″ TFT Active Matrix LCD (1680×1050) display designed to “bounce sound off the desk below”. Connectivity includes Firewire “400″ and USB 2.0, as well as standard AirPort Extreme (802.11g) and Bluetooth 2.0+EDR.

May 3, 2005 October 12, 2005
2.0 GHz PowerPC 970* (G5)
Details: The PowerPC 970 “G5″ has 64-bit data paths and registers with native support for 32-bit application code. It additionally includes the AltiVec “Velocity Engine” vector processor and “two independent double-precision floating-point units”.
1 1095
Soldered Integrated
Details: The processor is mounted directly to the motherboard.
667 MHz (3:1) 2.0 GHz (Built-in)
Details: 667 MHz frontside bus.
Open Firmware 1 MB
Details: Boot ROM and around 1 MB, other instructions are loaded into RAM (NewWorld).
32k/64k 512k
Details: 32k level 1 data cache, 64k level 1 instructional cache. The 512k on-chip level 2 cache runs at processor speed.
PC3200 DDR 400 MHz
Details: Supports 400 MHz PC3200 DDR SDRAM. If installing RAM in both slots, use matching memory for best performance.

Also see: How do you upgrade the RAM in the iMac G5 models? How much RAM of what type do these systems support?

512 MB 2.0 GB
None 2
Details: If non-matching RAM is installed, the 128-bit memory bus will operate as a 64-bit bus.
Radeon 9600 DDR SDRAM
Details: ATI Radeon 9600 with 128 MB of DDR SDRAM (AGP 8X support).
128 MB 128 MB
Details: Video cannot be upgraded.
20.0″ TFT 1680×1050
Details: This model has a 20.0″ TFT active matrix display with a 16:10 aspect ratio and a native resolution of 1680×1050. In the 16:10 aspect ratio, it also supports 1344×840, 1280×800, 1024×640, 840×524, and 800×500, and in the 4:3 aspect ratio it supports 1024×768, 800×600, and 640×480. Apple additionally reports a “typical” brightness of 230 cd/m, contrast ratio of 400:1, and viewing angle of 170 degrees horizontal and 170 degrees vertical.
Mirroring Only* 1024×768*
Details: Apple reports that this system has a “VGA output port for video mirroring on an external display or projector”, and supports output resolutions of “640 x 480 pixels at 60Hz, 800 x 600 pixels at 75Hz and 1024 x 768 pixels at 75Hz”.
250 GB (7200 RPM) Serial ATA (1.5 Gb/s)
8X DL “SuperDrive” None
Details: Apple reports that the slot-loading 8X DVD+R DL/DVD±RW/CD-RW SuperDrive “writes DVD+R DL discs at up to 2.4x speed, writes DVD-R and DVD+R discs at up to 8x speed, writes DVD-RW and DVD+RW discs at up to 4x speed, reads DVDs at up to 8x speed, writes CD-R discs at up to 24x speed, writes CD-RW discs at up to 8x, [and] CDs at up to 24x speed.”
56k v.92 10/100/1000Base-T
Details: Internal modem and 10/100/1000Base-T (Gigabit) Ethernet standard.
802.11b/g (Standard) 2.0+EDR
Details: AirPort Extreme (802.11g) and Bluetooth 2.0+EDR standard.
3 (2.0) 2 (400)
Details: Apple advertised that this system had a “total of five USB ports” counting three USB 2.0 ports on the system and two USB 1.1 ports on the keyboard. Two Firewire “400″ ports are shared – 8 watts.
AP/BL None
Details: Internal AirPort Extreme (802.11b/802.11g) and Bluetooth 2.0+EDR pre-installed.
Apple Keyboard Apple Mouse
Details: N/A
All-in-One iMac G5
Details: Integrated all-in-one “ice white” enclosure approximately two inches deep supported by an aluminum stand.
M9845LL/A Ambient Light Sensor
Details: The Apple order number should be unique to this system.
A1076 (EMC 2056) PowerMac8,2
3.6V Lithium N/A
Details: N/A
X 10.4 (8A428) X 10.5.8
Details: This system cannot run versions of MacOS X more recent than 10.5.8.
Classic Mode Only* Emulation Only
Details: *This model is capable of using MacOS 9 applications within the MacOS X “Classic” environment provided with MacOS X 10.4.11 “Tiger” and lower (“Classic” is not supported starting with MacOS X 10.5 “Leopard”). It cannot boot into MacOS 9. 
18.6 x 19.4 x 7.4 25.2 lbs. (11.4 kg)
Details: In inches – height by width by depth, (47.2 cm, 49.3 cm, 18.9 cm).