AN/UYK-8

The AN/UYK-8 used the same 30 bit word and instruction set of the AN/USQ-17 and AN/USQ-20 Navy Tactical Data System (NTDS) computers, but could have two processors instead of just one.

Instructions were represented as 30 bit words, in the following format:

   f  6 bits   function code 
   j  3 bits   jump condition designator 
   k  3 bits   partial word designator 
   b  3 bits   which index register to use 
   y  15 bits  operand address in memory

Numbers were represented as 30 bit words, this allowed for five 6 bit alphanumeric characters per word.

The main memory was increased to 262,144 words of core memory.

The available registers were:

• one 30 bit arithmetic (A) register.
• a contiguous 30 bit Q register (total of 60 bits for the result of multiplication or the dividend in division).
• seven 15 bit index (B) registers.