We have developed PC/104 single board computer (SBC) based embedded IOCs for our low level control systems. The PC/104 IOCs runs the operating system RTEMS and EPICS. Two types of control system configurations were used in our different applications, PC/104 SBC with commercial I/O cards and PC/104 SBC with custom designed FPGA-based boards. RTEMS was built with CEXP shell to run on the PC/104 SBC. CEXP shell provides the function of dynamic object loading, which is similar to the widely used VxWorks operating system. Standard software configurations were setup for IOC application development to ease the conversion of applications from VME based IOCs to PC/104 IOCs. Many new projects at Jefferson Lab are going to employ PC/104 SBCs as IOCs. Some applications have already been running PC/104 IOCs for accelerator operations. They have been proven to be reliable, easy to configure and low maintenance IOC platforms. The PC/104 - RTEMS IOC provides a free open source Real-Time Operating System (RTOS), low cost, easily installed, flexible, and reliable solution for accelerator control and 12GeV Upgrade projects.