Eee PC Research


  • 1 Pictures
  • 2 Specifications
  • 3 Datasheets
  • 4 Accessories
  • 5 Linux Hardware Output
  • 6 Chips and Connections
  • 7 Power and Signals
  • 8 Solid State Drive
  • 9 BIOS Chip
  • 10 Update BIOS
  • 11 Clear BIOS
  • 12 Expansion Bay
  • 13 Lid Magnet
  • 14 References


I've put together a pack with pictures of my Eee 701 4G showing detailed pictures of the motherboard. Both scans and close-up mosaic pictures of the motherboard are available




  • Width: 22.5 cm
  • Depth: 16.5 cm
  • Height: 2.1 to 3.5 cm
  • Weight: 920 grams




  • Logitech V470 White Bluetooth mouse

Other suitable accessories:

  • Logitech VX Nano mouse
  • Microsoft Bluetooth Notebook 5000 / 4000 mouse
  • LG GSA-E50L Slim DVD writer

Linux Hardware Output


00:00.0 Host bridge: Intel Corporation Mobile 915GM/PM/GMS/910GML Express Processor to DRAM Controller (rev 04)
00:02.0 VGA compatible controller: Intel Corporation Mobile 915GM/GMS/910GML Express Graphics Controller (rev 04)
00:02.1 Display controller: Intel Corporation Mobile 915GM/GMS/910GML Express Graphics Controller (rev 04)
00:1b.0 Audio device: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) High Definition Audio Controller (rev 04)
00:1c.0 PCI bridge: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) PCI Express Port 1 (rev 04)
00:1c.1 PCI bridge: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) PCI Express Port 2 (rev 04)
00:1c.2 PCI bridge: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) PCI Express Port 3 (rev 04)
00:1d.0 USB Controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB UHCI #1 (rev 04)
00:1d.1 USB Controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB UHCI #2 (rev 04)
00:1d.2 USB Controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB UHCI #3 (rev 04)
00:1d.3 USB Controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB UHCI #4 (rev 04)
00:1d.7 USB Controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB2 EHCI Controller (rev 04)
00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev d4)
00:1f.0 ISA bridge: Intel Corporation 82801FBM (ICH6M) LPC Interface Bridge (rev 04)
00:1f.2 IDE interface: Intel Corporation 82801FBM (ICH6M) SATA Controller (rev 04)
00:1f.3 SMBus: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) SMBus Controller (rev 04)
01:00.0 Ethernet controller: Atheros Communications, Inc. AR5007EG 802.11 b/g Wireless PCI Express Adapter (rev 01)
03:00.0 Ethernet controller: Atheros Technology Corp. L2 100 Mbit Ethernet Adapter (rev a0)

Chips and Connections

A simple diagram showing the major chips and connections on the motherboard.



Power and Signals

The diagrams below shows power, ground, and signals that's useful when modifying the Eee. All of the points are verified and confirmed working.



Solid State Drive

The solid state drive on the Eee is powered by a Silicon Motion SM223 CF flash controller and 4x NAND SLC-large-block flash chips from various manufacturers. The flash controller also has an ATA interface that is available via the free mini PCI-express pads in the expansion bay (see below for details).

NAND flash found:



For a little while there was confusion how the BIOS was stored. Speculation about parts of the SSD could be used for the BIOS, integrated chipset BIOS, or a unknown IC-chip.

Turns out the BIOS chip was covered by a adhesive label and the part number is Winbond 25X40VSIG. It features a 8-pin 512K serial flash.

Update BIOS

The easiest way to update the BIOS:

  • Download the BIOS zip-archive
  • Extract the '.ROM'-file to a USB flash drive
  • Rename the '.ROM'-file to '701.ROM' for Eee PC 4G 701
  • Reboot the Eee PC and press ALT+F2 during the first POST-screen
  • A black screen with the text 'Intel(r))915GM/...' will appear and the process will begin automatically
  • Press the POWER-button after the update is finish as described

Downgrade the bios by booting DOS and executing the AFUDOS utility:

  • Download the Bios Update Tool package
  • Extract and run the MakeBoot.cmd batch to format the flash drive and copy the required DOS and BIOS files
  • Reboot the Eee PC and press ESC to bring up the boot selection screen
  • Select the flash drive and boot into the Bios Update Tool menu
  • Answer the questions and finally pick the BIOS to downgrade to

The Eee PC BIOS Revisions page shows some tools to upgrade and downgrade the BIOS. As of version 0511, the ALT+F2 method does not allow downgrading to earlier versions, use the BIOS Update Tool instead.

Clear BIOS

There are two pads in the expansion bay labeled CLRTC, aka Clear Real Time Clock RAM, for clearing the CMOS settings. By shorting these two pads the settings are erased. Up-on booting a 'CMOS Settings Wrong'-prompt will appear and press either F1 for the setup or F2 to load defaults.

Image:Eee clear cmos.jpg

Expansion Bay

The expansion bay on the 4G machines is empty and the earliest machines (serial number starting 7A) had the mini PCI-express socket fitted. On all the newer revisions of the model the socket is removed and there's only the traces left, and rumors speculate that it's just a matter of mounting a fitting socket and the connection will work. Although with some caveats.

The SSD will be disabled once a card is inserted into the mini PCI-express slot. The reason for this behavior is that Asus could decide if the SSD drive should go on-board (non-upgradable) or in the expansion by slot (upgradeable). That's exactly how the 8G works, the SSD is installed in the expansion bay and leaving the on-board SSD traces empty.

It's possible to disable the disable-behavior by tracing the 3v3 points from clean spots on the motherboard, unverified.

Asus used a non-standard mini PCI-express layout for the expansion bay, it has one PCI-express lane, USB connection and, more interestingly, an ATA interface connected via the SM223 compact flash controller (see pdf link). The compact flash cards has a interface electronically identical to ATA and also a IDE controller on-board, making it possible to use a CF card as a very fast alternative boot device.

Mini PCI Express Pinout

The Mini-PCI Express 52-pin connector pin out is listed below. I still need to verify the pin out table for errors.

MiniCard Pinout
Pin # Signal Name Pin # Signal Name
51 Reserved 52 +3.3V
49 Reserved 50 GND
47 Reserved 48 +1.5V
45 Reserved 46 LED_WPAN#
43 Reserved 44 LED_WLAN#
41 Reserved 42 LED_WWAN#
39 Reserved 40 GND
37 Reserved 38 USB_D+
35 GND 36 USB_D-
33 PETp0 34 GND
31 PETn0 32 SMB_DATA
27 GND 28 +1.5V
25 PERp0 26 GND
23 PERn0 24 +3.3Vaux
21 GND 22 PERST#
19 Reserved (UIM_C4) 20 Reserved
17 Reserved (UIM_C8) 18 GND
Mechanical Key
5 Reserved 6 1.5V
3 Reserved 4 GND
1 WAKE# 2 3.3V

Image:Eee mini pcie removed.jpg Image:Eee flash_con pinout.png

Expansion bay dimensions, inside under the expansion bay door:

  • 35 x 68.5 x 8-10 mm (W x L x H)
  • Card length (from connector to fastening screw): 68 mm (non-standard)

Lid Magnet

There is a strong magnet inside the top lid and a sensor on the motherboard that's used to detect when the lid is closed or open. You can figure out where the magnet is located by sliding a paperclip back and forth on the bottom-left side. The corresponding sensor is located between the ethernet, battery and DC-jack on the motherboard, as shown.

Image:Eee magnet lid.jpg Image:Eee magnet sensor.jpg

In Linux, at least the default Xandros install, the lid function can be controlled via /etc/acpi/


Asus EEE Webcam Wiring Information

The webcam's wiring inside the screen bezel is a USB connection. The wires differ from standard usb colors.
Here is a conversion chart.

Model : ASUS EEE 4G (7A)

Pin # Desc Standard Color EEE Camera Wire Color
1 +5(bus)


dashed red
2 data- white orange
3 data+ green white
4 ground black black

Note: During modding, if the bios resets,
the 'internal camera' setting will be turned to disabled(default).
This will cut power until you re-enable it via the bios.
The bios option will not be available if there is no device connected.