|Year Introduced:||1974 (TBC)|
|Word Size:||16 bit|
|Memory Size:||4kw - 64kw|
|Operating System:||SINTRAN III/12|
The NORD-12 was a slightly slower and memory-limited variant of the NORD-10
Comparision with NORD-10
The NORD-12 was mostly compatible with the NORD-10, but with some limitations.
- It was slightly slower (500ns microinstruction cycle time vs 300ns for the NORD-10)
- It did not support the paging option of the NORD-10 and thus the memory could not be extended above 64 kwords
- The only memory option was 4096 bits/chip MOS memory, while the NORD-10 could use various types (including core).
- It had a tiny difference in the floating point handling, missing an internal bit (TG) used to round the last significant bit of floating point operations. Thus rounding errors would always be truncated, i.e. the least significant bit would sometimes be 0 where the NORD-10 operation would be 1.
- There are some small differences in hardware interrupt handling, missing the IIE (Internal Interrupt Enable) and IIC (Internal Interrupt Code) registers. But it's possible to hardwire NORD-12 interrupts directly to level 14.
- Unlike the NORD-10 the NORD-12 could not be equipped with a NORD-1 input/output channel option
- The parity mechanism is slightly different
Other than the above, the NORD-12 and NORD-10 are fully compatible. In particular, the I/O system is the same, and all peripheral and interface cards can be used in both systems.
As the NORD-10, the NORD-12 also included a battery which could retain the memory in case of power failure. For the NORD-12 the memory standby time was up to 30 minutes.
- NORD-12 reference manual