Synchronous RS-232 serial connectivity is an appropriate choice when rigorous security and intensive data integrity protocols are required for high-speed serial communication. It is the communication method of choice for a wide variety of military and commercial systems such as satellite monitoring, radar control, GPS systems, flight recorder data transfers, and HF (High Frequency) e-mail systems to name a few. Quatech's single port RS-232 synchronous serial PCMCIA card supports asynchronous data formats as well as byte-oriented synchronous protocols such as BiSync, and bit-oriented synchronous protocols such as HDLC and SDLC. The card's robust design provides 1024-byte transmit and receive FIFO's, and a SCC with advanced internal functions including on-chip baud rate generators and digital phase-lock loop (DPLL) for recovering data clocking from received data streams. The cards are available with a convenient detachable cable, or with a ruggedized attached cable for extreme environments. Quatech's frame-level HDLC and Bisync driver, SyncDrive, is included for Windows 95/98/Me and OS/2. For Windows 2000/XP, SyncDrive Plus, a bit-synchronous SDLC/HDLC driver is also included. Both SyncDrive packages are not application programs themselves, but provide C callable routines and C data structures designed to aid users in the development of their own application software.