Ten years have passed since the current control system started the operation of the TRISTAN accelerator. The system uses CAMAC as a front-end electronics, and they are controlled by 25 Hitachi process computers linked by a N to N token ring network. In order to have the ability to perform complicated accelerator operations, there is a strong request to renew these 25 process computers. Firstly, we review how we will rejuvenate the current control system under some constraints, such as the lack of man-power, limited time and financing. This is followed by proposals for the next step of rejuvenation.