Keyboard drivers are the next thing you need after a font in order to work with Church Slavic text. Entering text using the Character Map (or some similar utility) is not just slow, it can also cause problems like improper positioning of diacritical marks. Several different options are available for entering Church Slavic text on the keyboard.
Keyboard entry may occur either by use of a Church Slavic keyboard, designed for typing only in Church Slavic, or by use of an Extended Russian keyboard, designed for typing mostly in modern Russian and occasionally in Church Slavonic. If you are typesetting large amounts of Slavonic text, you will probably want the first option. If you occasionally edit a few lines of Slavonic text and do not want to learn a new layout, you will undoubtedly want the second version.
The Church Slavonic virtual keyboard allows you to type in Church Slavonic without installing any software. Just enter the text into your browser and then copy/paste it into a text editor. Both the Church Slavonic keyboard and the Extended Russian are available (click on CU in the lower left-hand corner of the virtual keyboard to switch layouts).
Keyboard drivers for different operating systems:
For Russian Extended and special Church Slavonic keyboard drivers, see m17n-cu package for IBUS / m17n. Download from GitHub
Physical Keyboard Driver for USB/Bluetooth keyboards: download APK Alpha phase software! for testing purposes only!
Documentation for all keyboard layouts and installation instructions in PDF: download