Quote Originally Posted by ntenny View Post
I don't clearly understand, and it would be interesting to learn, what some of the "weird" chemicals in the HC-110 patent formula are there for.
To provide halide solvency and replace the sodium sulfite used in conventional developers HC-110 contains the addition product of an amine and sulfur dioxide. To replace potassium bromide which is an inorganic salt and not soluble in glycols an addition product of an amine and hydrogen bromide is used. These are not chemicals that are readily available from chemical suppliers. As I mentioed Kodak manufactured several of the components of HC-110 just for this developer.

As pointed out there is a homebrew replacement for HC-110. It is called D-76.