The 73D2248A/2348A Device Sets consists of two CMOS integrated circuits which provide the data pump and protocol functions required to implement a high performance 2400 bit/s modem with error control and data compression. The 73D2248A basic modem function is provided by the 73K224L modem chip and is compatible with CCITT V.21, V.22, V.22bis and Bell 103 and 212A protocols. The error control functions are provided by modular software running in the 73M2910 controller. Modules are available for MNP4, and V.42. Compression software modules can be added to the controller; MNP5 and V.42bis are available. Provisions for customization of the command set are provided, forming the basis for an international modem.