| 16-line Programmable I/O Port | Interface to one Thurnall device. Uses Zilog PIO. Fully decoded, so it doesn’t conflict with other devices. Interfacing to more than one device requires the Thurnall motherboard. | Timex/Sinclair 1000 |
| 4-channel Relay Box | Use with Thurnall I/O board to switch low-current household equipment. | Timex/Sinclair 1000 |
| 8-way Indicator Unit | 8 LED output; displays binary equivalent of the data on one port of the Thurnall I/O board. | Timex/Sinclair 1000 |
| 8-way Switch Unit | Provides a byte-wide input interface to the Thurnall I/O board. | Timex/Sinclair 1000 |
| 8-way Transistor Driver | Use with Thurnall I/O board to switch low voltage devices. | Timex/Sinclair 1000 |
| Joystick | Required the Thurnall I/O board to interface to the computer. | Timex/Sinclair 1000 |
| Motherboard | Expansion board for use with other Thurnall modules. Required to connect more than one device to the I/O board; connect up to four Thurnall modules. | Timex/Sinclair 1000 |
| Sound Unit | Programmable sound unit with built in loudspeaker, allow programmable generation of a whole range of rounds from music to special effects. | Timex/Sinclair 1000 |
