One big problem – on a character mode terminal such as a VT100, the host gets sent every single keystroke. So any key combination can be used as an "action key"

One big problem – on a character mode terminal such as a VT100, the host gets sent every single keystroke. So any key combination can be used as an "action key" – such as the slash key (/) used to open the Lotus 1-2-3 menu system. By contrast, on block mode terminals such as 3270, only a restricted subset of keys – such as ENTER and function keys – triggered a message being sent to the host, the rest of the keys were interpreted locally only. (Was there some mechanism to allow the host to redefine an arbitrary key as an action key? Not that I know of.) How did Lotus 1-2-3/M address this? From what I understand, they adopted an approach commonly used in 3270 applications – a fixed area at the bottom of the screen was reserved as a "Command area". You would type your slash sequence there, and then press ENTER. The whole sequence would be sent to the host. If what you typed was not a full command, just the prefix of a command, I believe it would display you a menu showing the command options, similar to how 1-2-3 worked on other platforms. But it also was a problem with things like scrolling off the screen. On 1-2-3 on other platforms, you could just use the cursor keys, and the screen would scroll immediately. Under 3270, the cursor keys are implemented locally, so you'd have to use a function key or command to scroll instead.