Next: The ST-6 Up: CCD Systems and Previous: The Lynxx . The SBIG ST-4 uses the same CCD chip that is used by the Lynxx. The ST-4 uses a CPU box as opposed to a card that must be installed in the computer. This makes the ST-4 more portable than the Lynxx, since it can be run by a laptop computer for imaging, or with just the CPU box for guiding. ... The ST-4 is also capable of moving the telescope. ... Its purpose is to allow the CCD computer to communicate with the telescope's drive. ...