3033

3033 is the ND-100 CPU with CX option board. It contains the CPU, bus arbitration logic, memory control and other subsystems. It also has the Real time clock and the I/O for the serial console.

Switches and indicators
As seen from the top, when the card is in the card crate (components on the right hand side). console speed thumbwheel switch ALD thumbwheel switch green LED - cpu self test ok red LED - cpu self test not ok

Console speed setting Setting 14 and 15 is not defined (not used?).
 * 0 - 110 baud
 * 1 - 150 baud
 * 2 - 300 baud
 * 3 - 2400 baud
 * 4 - 1200 baud
 * 5 - 1800 baud
 * 6 - 4800 baud
 * 7 - 9600 baud
 * 8 - 2400 baud
 * 9 - 600 baud
 * 10 - 200 baud
 * 11 - 134.5 baud
 * 12 -  75 baud
 * 13 -  50 baud

Connectors
General: the A and B connectors are used for I/O, the C connector is used for the ND-100 Bus. On this CPU module, the B connector connects to the memory management module in slot 2.

I/O Devices on the card
The real time clock (device numbers 10 - 13) is always located on the CPU board. The terminal (Terminal 1) with device number 300 (octal) is located on the CPU board, unless a strap on the CPU board is removed.

Current Loop interface
The current loop interface (AKA Terminal 1 AKA console), located on the CPU board, has device number 300. The device register address range is 300 - 307.

Real-Time Clock
The real-time clock on the CPU board has device number 10. The device register address range is 10 - 13.