The GRAK NVRAM board contains a programmable 11-in 8-out lookup table for controlling the behavior of a robot. The table operates in a latched synchronous mode with update rate of approximately 100 Hz. The core Non-Volatile Random Access Memory chip can be removed and then reconfigured with the Engrammer box. Alternatively, by adding a cable the UART board can be used to download control programs directly from a personal computer. The NVRAM board has a special "lock-out" jumper to prevent inadvertent alteration.

The NVRAM board also contains two independent square wave oscillators. The duration of the high and low states can be adjusted using trimpots on the back of the board. The oscillators can also be forced to the low state by bringing the "Stop" line high. When restarted, the oscillators will generate a slightly elongated low pulse before resuming normal operation.

Block Diagram

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