A minicomputer(?) introduced by Data General in 1969, with four 16-bit accumulators, AC0 to AC3, and a 15-bit program counter. A later model also had a 15-bit stack pointer and frame pointer. AC2 and AC3 could be used for indexed addressing and AC3 was used to store the return address on a subroutine call. Apart from the small register set, the NOVA was an ordinary CPU design.
Memory could be accessed indirectly through addresses stored in other memory locations. If locations 0 to 3 were used for this purpose, they were auto-incremented after being used. If locations 4 to 7 were used, they were auto-decremented. Memory could be addressed in 16-bit words up to a maximum of 32K words (64K bytes). The instruction cycle time was 500 nanoseconds(?). The Nova originally used core memory, then later dynamic RAM.