Boss Serial number decoder Enter your Boss serial number: This serial number decoder accepts all types of Boss compact pedal serial numbers. The different types are shown in the images below. Algorithm by Steve Tucker - Praise Technologies / Borge Trongmo - BossArea Type I - Used from late 1977 until early 1981 Type II - Used from early 1981 until early 1989 Type III - Used 1988-1989 Type IV - Used from March 1989 until present Note that the algorithm for serial numbers of type I, II and III are not confirmed yet and must be regarded as at least +/- two months of the real production date. You may also find odd serial numbers that doesn't match the expected year of production. If you do, please post on the forum.