CHARI 0xFE,d ; read 1stchar CHARI 0xFF,d ; read 2ndchar LDBYTEA 0xFE,d ; load 1stchar ADDA 0xFE,d ; add 2ndchar to low byte(big endian!) ANDA 0x0F,i ; keep low 4 bits ORA 0x30,i ; convert to ascii STBYTEA 0xFD,d ; store for output CHARO 0xFD,d ; write result STOP.END Hello, I mostly understand this assembly code, but am confused with this line: "ANDA 0x0F,i". This program inputs two single-digit numbers, adds them and then outputs their single-digit sum. Apparently, we are keeping the low 4 bits. What exactly is meant by this, specifically with what the program is trying to accomplish?