x1400 working with Lion 10.7.2 with full resolution and support QE/CI on 64bit kernel!
1. Using any text editor, edit the info.plist file from ATIRadeonX1000.kext and change the following string: from 0x71461002 to 0x71451002 (because the dev id for the Mobility x1400 is 7145.
2. Download a freeware program called softMCCS. This is used to extract your EDID information for placement inside the RadeonHD.kext info.plist.
3. Once downloaded, launch softMCCS and go to file->save EDID as->choose file type "viewsonic EDID file"->save your edid.dat.
4. Open this edid.dat file with any text editor, and remove all the white space from the beginning of the file, and remove the headers and columns (so essentially, you're left with rows and columns of xx data). Now format all of these xx data bits into groups of 8 followed by a space, so you basically have 32 chunks of xxxxxxxx data (xxxxxxxx xxxxxxxx etc...). This code save as hex code in hex editors. And encode this hex file in base64 format(example totalcmd - encode file - mime).
5. Download RadeonHD.kext from here from section [10/12/2009 update]:
10.6 (32&64) RadeonHD.kext.noBios10.6.zip ( 346.57K )
6. Now copy and paste this code in base64 into the RadeonHD.kext info.plist file, under the section <key>EDID</key><data>
7. Install either flavour of OSX (might work with other versions but I haven't tested this yet). Using the free program KextHelper, first install your modified ATIRadeonX1000.kext, repair disk permissions using Disk Utility, and reboot.
8. Again using KextHelper, then install your modified RadeonHD.kext, repair disk permissions, and reboot. If you get a kernel panic, reboot using -v -f commands.
9. If all boots well, you should now be able to change your screen resolution to 1400 x 1050 with QE/CI.
10.10.6.8 and 10.7 updated the graphic driver framework, make present RadeonHD.kext not working any more. You need to replace with 10.6.7(i use 10.6.3) IOGraphicsFamily.kext, IONDRVSupport.kext, IOPCIFamily.kext and AppleACPIPlatform.kext on 10.6.8/10.7.
The only problem I have now is mouse tearing. I install program MouseLocator and change cursor.
(how to create from this topic and ATI HD framebuffer driver (10.5/10.6) )