  On Board Data Handling (OBDH) has functions to monitor, control, acquire,
analyze, take a decision, and execute the command. OBDH should organize the
task between sub system. OBDH like a heart which has a vital function. Because
the function is seriously important therefore designing and implementing the
OBDH should be carefully, in order to have a good reliability. Many OBDHs have
been made to support the satellite mission using primitive programming. In
handling the data from various input, OBDH should always be available to all
sub systems, when the tasks are many, it is not easy to program using primitive
programming. Sometimes the data become corrupt because the data which come to
the OBDH is in the same time. Therefore it is required to have a way to handle
the data safely and also easy in programming perspective. In this research,
OBDH is programmed using multi tasking programming perspective has been
created. The Operating System (OS) has been implemented so that can run the
tasks simultaneously. The OS is prepared by configuring the Linux Kernel for
the specific processor, creating Root File System (RFS), installing the
BusyBox. In order to do the above method, preparing the environment in our
machine has been done, they are installing the Cross Tool Chain, U-Boot,
GNU-Linux Kernel Source etc. After that, programming using c code with
multitasking programming can be implemented. By using above method, it is found
that programming is easier and the corruption data because of reentrancy can be
minimized. Keywords- Operating System, PC-104, Kernel, C Programming
