This is a one of a kind drive unit built in 1984 for use with my Celestron 11. I have since computer controlled the telescope and no longer have a use for the drive. The system has given me almost 20 years of rock solid service. I have never had to replace one componet in this system since it was built. The drive electronics are built around a Bradford-West Quartz drive board. William-Bell sold these boards back in the 80's. Four BCD switches give the unit over 10,000 selectable drive rates. I added a digital readout display which updates as you change drive rates using the BCD switches. This allows you to read the drive rate in total darkness. The unit was built to power an AC syncronized motor and 12 VDC Declination motor. The system has two on board clocks, one displays Sidereal Time, the other Universal Time. The hour, minute and second times can be set for each clock from the back panel of the drive unit. This drive corrector also has a built in digital timer on the hand paddle for monitoring your photo or ccd exposures. The timer can be turned off by a switch on the top of the hand paddle or reset to 0 by holding down the reset button for 5 seconds. I also wired this drive for use with an ST4 autoguider unit, but this system can be modified to work with almost any autoguider. The drive, clocks, timer and autoguider electronics all function perfectly. I am asking $300.00 plus shipping and insurance for this drive. The digital displays on this device are brighter than they appear in the photo below, but have been washed out by my camera's flash unit. Thats for looking!