The embodiments described herein can be used to enable one-time or few-time programmable memories to work with existing consumer electronic devices without requiring a firmware upgrade, thereby providing backwards compatibility while minimizing user impact. The issuer models the initial financial parameter data associated with a corresponding proposed financial instrument based on at least market data relevant to the issuance of the proposed financial instrument. Thus, for example, the DSV value of the encoded data is recorded so that the DSV value changes continuously once 50 frames of data or more. The biasing members bias the keys toward the normal rest position.