3 year ish veritas system no alarm code or manual help?

hi just moved in to new home with veritas alarm system i think its 3 years old no led disply probab R8 but not sure. problem is no manual given and no alarm code. Is it possible to reset the codes and get the alarm up and running again? i don't want to guess its 1234 then alarm goes off and i'm stuck with alarm going off! Any help would be great. thanks