Ben Ryves had some DS18B20 1-wire temperature sensors and he puts them to use.

1-Wire serial bus, a bus named for the way that its single data line can also be used to parasitically power the devices on the bus. Electrically the bus is open drain with a pull-up resistor that idles in the high state which any device can drive low. The master initiates all communication and you can have multiple peripheral devices connected to the bus in an arrangement called a MicroLAN.

Now that I had a collection of temperature sensors I thought it might be worth revisiting on the Cambridge Z88.

To connect 1-Wire devices to the Z88 some sort of adaptor is required and one that plugged into the computer’s serial port seemed like a sensible enough option. The Z88’s serial port hardware normally handles all the communications for you however it is possible to directly control the logic levels of the serial port’s output pins and read back the status of the input pins via some hardware registers.

See how Ben implements his 1-Wire system in the post here.