Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for determining word boundary likelihoods in potentially incomplete text. The vertical organic light emitting transistor assembly comprises a firstsecond vertical transistor and a firstsecond organic light emitting diode perpendicularly integrated with the firstsecond vertical transistor, respectively. The data processing circuitry is configured to set the mask value to a first value in the data store in response to executing critical code and on termination of execution of the critical code to reset the mask value to not store the first value.