The ND-100 has a 16-bit word format. The bits are conventionally numbered 0 to 15 from right to left. The most significant bit is number 15. The ND-500 has a 32-bit format. A 16-bit word consists of two bytes of 8 bits each. The contents of an ND-100 word is conventionally represented by a 6-digit octal number. The representation of a negative number is in the 2's complement range -32768 > x > 32767. Thus, the word with all 16 bits set to zero is 000000 (octal), while the word with all bits set to one, ie., -1, is represented as 177777 (octal).
- Norsk Data Document ND–06.026.01 ND-110 Functional Description , from Glossary
- Norsk Data Document ND–05.009.03 NORD-500 REFERENCE MANUAL , from Preface