Apologies, this may be off topic. Ham radio operators are the probably the only community that might have used Handicode. Back in 2002, a company "Microsystems Software" made a DOS program that allowed a morse code keyer to be used as an input device for a computer. They appear to be long out of business, as their website is down, and the internet wayback archive only contains references to Cyber Patrol.
I'm trying to create a similar device for a blind user that used to own one. The first step is to track down a copy of the documentation so I can reproduce the extended morse code characters, such as ALT, CTRL, and SHIFT.