last year, I saw this at computer history museum in mountain view. it was impressive.
photo and text from wikipedia.
The CDC 6600 was a mainframe computer from Control Data Corporation, first delivered in 1964. It is generally considered to be the first successful supercomputer, outperforming its fastest predecessor, IBM 7030 Stretch, by about three times. With performance of about 1 MFLOP, it remained the world’s fastest computer from 1964–1969, when it relinquished that status to its successor, the CDC 7600.
The system organization of the CDC 6600 was used for the simpler (and slower) CDC 6400, and later a version containing two 6400 processors known as the CDC 6500. These machines were instruction-compatible with the 6600, but ran slower due to a much simpler and more sequential processor design. The entire family is now referred to as the CDC 6000 series. The CDC 7600 was originally to be compatible as well, starting its life as the CDC 6800, but during the design compatibility was dropped in favor of outright performance. While the 7600 CPU remained compatible with the 6600, allowing portable user code, the PPUs were different, requiring a different operating system.
A CDC 6600 is on display at the Computer History Museum in Mountain View, California.