ZBasic Language Reference
193
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
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