Page 197 of 229 Start Back Next End ZBasic Language Reference 187 ZBasic Microcontrollers The second alternate serial interface is shown in the diagram below. This circuit produces a serial output signal that meets the RS-232 standard by using the negative voltage on the receive line to provide a reference for the output level. Although the parts count is higher, the circuit uses inexpensive and non- critical components. Alternate Serial Interface Circuit #2 Reset Circuit You may also want to incorporate a reset button in your circuitry. If so, a normally open, momentary contact switch may be connected directly between pin 4 of the ZX and ground. If other circuitry in your application also needs the reset signal, you may want to isolate that circuitry from the ATN resets using a buffer gate or a diode. A suggested diode isolation circuit for the reset line is shown below. Reset Signal Isolation