What if?
Large piston driven steam engines that pushed, and pulled the world into the modern era, and for the most skill to quickly design, build, install such behemoths is gone. What if we were to try and build a steam engine using modern technology, would we be able to make any improvements on controllability if we used a computer instead of mechanical controls?
Why Corliss?
On a steam engine the valve gear is the mechanical system that allows for the admission of steam into the pistons causing movement. The Corliss valve gear, was one of the most developed versions of this, with a high degree of control on the engine's speed and economy while operating.
What makes Corliss valve gear interesting is that it uses four independent valves to control the flow of steam, with there being two valves on each side of the cylinder. The allows for the time of steam being admitted to the cylinder, the time that steam is allowed to expand (work), and the time for the remaining steam pressure to be exhausted can be finely tuned.
Sticking with this idea of four valves per cylinder we could replace those valves with solenoid valves and a sensor eliminating the complex mechanical system using a governor.