I figured out the problem ( I think ) and got myrast to install:

Visit this site: http://www.ubuntuupdates.org/package/core/precise/main/base/libdb4.8

Under "Download "libdb4.8"" - I clicked the "64 bit deb package"

On my computer, everything is downloaded to the ~/Downloads folder. To install type:

$ sudo dpkg -i ~/Downloads/libdb4.8_4.8.30-11ubuntu1_amd64.deb

Then you can install myrast

$ sudo dpkg -i ~/Downloads/myrast-runtime_1.0-1ubuntu1_amd64.deb

$ sudo dpkg -i ~/Downloads/myrast_33-1ubuntu2_amd64.deb

Depending on the system, you might also find that, besides lidb4.8, you need libwxgtk2.8-0. I could not find this on the repos, so I downloaded by following the instructions found here.

Those instructions are:

1. Add the following line to /etc/apt/sources.list:

# deb http://www.deb-multimedia.org jessie main

2. Update the package index:

# sudo apt-get update

3. Install GPG key of the repository:

# sudo apt-get install deb-multimedia-keyring

4. Install libwxgtk2.8-0 deb package:

# sudo apt-get install libwxgtk2.8-0