In October 1995, a CMOS brain chip consisting of two 8 x 17 multiplexed sub-arrays designed to measure electrical potentials at the cortical column level, was implanted on the somatosensory cortex of a laboratory rhesus monkey. Electroencephalograph (EEG) and averaged evoked response (AEG) data were taken over a period of 40 minutes. The brain chip was replaced with an identical chip, and data were again taken for 40 minutes. In both instances AEG signals of approximately 150 muVpp were recorded. Additionally, the first implanted chip recorded three phases of data: (1) AEG; (2) large clock noise (during a period where the chip appears to have burned the cortex); (3) AEG-like signals of magnitude, 100 muVpp, with substantially improved signal to noise ratio. All data were taken while the monkey was under general anesthesia. The monkey was euthanized immediately after the experiments, due to a pre-existing abdominal cancer.