ND-100 card crate

Crate sizes
A small cabinet has a 12-position card crate. A large cabinet card crate can hold up to 21 cards.

Card size
A standard ND-100 printed board module size is 366.8 mm x 280 mm.

Connectors
Every card has at least one 96 pin connector (the "C" connector) used for connection to the ND-100 Bus. In addition, a card may have one or two additional 64 pin connectors ("A" and "B"). Connectors A and B are defined for each individual card that uses them. They are used by I/O controllers for connections to external devices.

CPU card location
The CPU module is normally located in position number 1 in the card crate. When the memory management module is present, it is placed in position number 2.

Placement rules
The CPU module is placed in position number 1. The memory management and cache module (if present) is placed in position number 2.

I/O module placement
There should never be empty modules between the CPU and the last I/O module. Expansion is from left to right.

Memory module placement
Memory modules should be placed from the rear position (12 or 21) and expanded towards the CPU module.

Expansion
The ND-100 Bus can be extended to any number of other ND-100 buses by a driver and a receiver module.