I have at home a memory bank from a CDC Cyber two-hundred-and-something (?) which is 18 bits wide. I had always assumed that this was 16 bits plus two parity but it doesn't fit into 60 bits either way. (Memory bank is huge quantities of 40ns and 45ns 64k x 1 static RAMs surface mounted on both sides of numerous daughter boards. Each daughter board is 64k x 18 and they stack four deep all over the "mother board" of the bank.) I always meant to use this in something, but somehow I never got around to it... Philip.