The newest version of MMSSTV is by YNUIQ and starts in Spanish. To change to English (Ingles) CLICK Opciones, then Configurar MMSSTV(O), then Misc then in the lower right Click Ingles and OK.
I use Omni Rig to go between MMSSTV and my Yaesu FT-991A. First download and install Omni Rig 120 and configure for your radio. Also you will need to set up your sound card and such.
EASY PAL is a Digital SSTV program. The Yaesu FT-991A is not listed for CAT Control, you I needed to fill in USEr CONFIG for Cat Control. The FT-991A Cat Control Manual uses ASCII characters. Ex TX1: to turn on the Transmit. EASY PAL wants Hexdecimal Strings, Ex 5458313B. There is an ASCII to HEX Converter for both Easy Pal and DIGTRK Cat Control.