In your minicom config file (/etc/minirc.x or .minirc.x) put:
pu rtscts Yes
where Yes fot ANSI, No for VT102.
Here's what it currently is:
# more minirc.dfl
# Machine-generated file - use "minicom -s" to change parameters.
pu port /dev/ttyUSB0
pu baudrate 115200
pu bits 8
pu parity N
pu stopbits 1
pu backspace BS
pu rtscts Yes