I want aomeone to explain what this program do

Not all of it but 4-7 lines what each operation do please

.ORIG x4000 AND R6 , R6, #0 ADD R6, R7, #0 AND R1, R1, #0 ADD R1, R1, #4 AND R3, R3, #0 LEA RO, x PUTS GETC :Starting address of progran LOOP LD R2, 8 ADD R2, RO, R2 BRn LOOP LD R2, 57 ADD R2, RO, R2 BRnz UALID LD R2, 65 ADD R2, RO, R2 BRn LOOP LD R2, 78 LD R, 65 ADD R4, R4, #10 ADD R2, RO, R2 BRnz VALID LD R2, 97 ADD R2, R8, R2 BRn LOOP LD R2, 182 LD RI, 97 ADD R4, R4, #10 ADD R2, RO, R2 BRp LOOP BRnz UALID UALID PUTC ADD R3, R3, R3 ADD R3, R3, R3 ADD R3, R3, R3 ADD R3, R3, R3 ADD RO, RO, R ADD R3, RO, R3 ADD R1, R1, #-1 BRnp LOOP AND RO, RO, #0 ADD RG, RO, R3 JMP R6 48 57 6s 97 FILL xFFDO FILL xFFC7 .FILL xFFBF 70.FILL XFFBA .FILL xFF9 102-FILL XFF9A .END