I used this software when my mom was battling ALS: https://www.optikey.org/ which ran on a < $1k computer At the time, the other options were much more ex

I used this software when my mom was battling ALS: https://www.optikey.org/ which ran on a < $1k computer At the time, the other options were much more expensive (> $10-15k) which were sadly out of out budget.