摘要 |
In a microprocessor controlled machine, the microprocessor employs a number of pluggable control memories, at least one of which is essential in each cycle of operation of the machine. To ensure that a cycle is not started when the essential module is not operable, a start signal is coupled from an output port 261 to an input port 241. It is then transferred, under the control of code from the essential module to a further output port 262 to operate the machine starting circuits 27 and 28. Thus, if the essential module is not operable, the machine does not start. |