The serial number format could apply to several different manufacturers, however the triangular clamp stop/locator suggests Miyata, in which case it would be a 1984 frame. The year is reasonable given features like top tube tunnels and a set of bottle bosses. The presence of a cable stop as opposed to shifter bosses, in conjunction with the era, indicates an entry level frame and this is supported by other features such as the stamped rear dropouts. However, the frame characteristics do not match any catalogued Miyata model for the period, so it may be a contract manufactured frame for a brand such as Koga-Miyata or Univega.

The frame may be hi-tensile steel or a CrMo main triangle with hi-tensile stays and forks. The best indicator to determine the main triangle composition would be the seat post diameter.