This record contains three blank MINC circuit boards. These three are identical. These three boards have four connectors on the bottom, with silver coating on the right and left sides. On these three boards, side 2 has the words "4 Channel D-A" soldered. The date "JUL 22 1977" is stamped in black ink on side 1 of these boards. The manufacturer logo is soldered on the top right corner of side 1.