Three Model 500 versions were sold: 500: The board. 500-1: Fully enclosed board with power supply, reset switch and two standard terminal connectors. 500-8: A 500 board in an eight slot Challenger case with power supply.
OHIO Scientific presented later an enhanced version called SuperKit. It was a 3 board-set with a Model 500 board without the serial interface, a video board, a 8 slot backplane board and a modified version of the BASIC ROM allowing a direct use of the video board. A TV set could be used with an optional RF aerial modulator