This is an older phone and as such, the internet isn't as saturated as I'd like with information on how to create a custom background image for this model.

Without needing to fire up your old Windows 3.1 desktop to export the proper file, here's steps using up-to-date applications in Linux.

Using Gimp, create a new image:

  1. File > New
  2. Image size: 90 (width) X 56 (height)
  3. Open Advanced Options
  4. Color space: Greyscale
  5. Precision: 8-bit integer
  6. Gamma: Linear light
  7. Fill with: White

Make or import your custom logo/image.

Save the image:

  1. File > Export As...
  2. Name your file with a .bmp extension.

Convert the file to an older version of BMP:

convert <exported file>.bmp -compress none BMP3:<converted file>.bmp

You'll need ImageMagick tools installed to use the convert application.

Host the converted file on an internal or private web server, and make the necessary changes in the SIPDefault.xml file to direct the phone to the image's hosted location (via the logo_url setting).