The first Cray-1 system was installed at Los Alamos National Laboratory in 1976. The National Center for Atmospheric Research (NCAR) was Cray Research's first official customer in July 1977, paying US$8.86 million ($7.9 million plus $1 million for the disks). The NCAR machine was decommissioned in January 1989.
The Cray-1A weighed 5.5 tons including the Freon refrigeration system. The computer had a 'horse-shoe' cross-section in order to reduce wire lengths within the casing, no wire in the system was more than four feet long (1.2 m). It used vector processors and contained 200,000 specialized ECL circuits. The CRAY-1A had a 12.5-nanosecond clock (80 MHz), 64 vector registers, and 1 million 64-bit words of high-speed memory (8MB of RAM). It could execute over 80 million floating-point operations per second (MFLOPS), and later Cray-1s increased this to a world-record speed of 133 MFLOPS.
In 1978, the first standard software package for the Cray-1 was released, consisting of the Cray Operating System (COS), the first automatically vectorizing Fortran compiler (CFT), and the Cray Assembler Language (CAL). Later machines ran UniCOS, the Cray flavour of UNIX.
Priced from $5M to $8M, around 80 Cray-1s of all types were sold.