Line ends halfway in Terminal Emulator

When I'm typing, a new line is started, as if I ran out of space. Is it possible to set the terminal "width"?

For example, this is typed continuously, without pressing enter:

/ $ aaaaaa
aaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaa

(I've used ash found in BusyBox v1.23.1-Stericson as shell, on Android 4.4.)