Down East Computers of Greenville, N.C., has produced an allpurpose voltage and temperature measuring system designed to interface with the T/S1000, ZX81 computer or any Z80 based system. The Votem, as it is called, containing all the necessary hardware and software, is an ideal link between the digital and the real world (analog). It is sold both assembled and in kit form.
For the kit, Down East appears to have spent a considerable effort on component selection to insure a good PC board layout and ease of user connections. The board layout is easy to understand and more important, it allows for easy servicing (should it be needed).
All the parts are labelled directly on the board and correspond neatly with the schematic diagram supplied. The connections are quite accessible for easy assembly. They too are well labelled, which helped us avoid any “fatal” mistakes. To make it even simpler and faster, no soldering connections are made to the board. They are all made via jacks or terminal screws.
The manual is extremely comprehensive and written to be understood. It starts at basic principles and guides the user, stepby-easy-step, through the assembly, operation, calibration and features of the Votem.
Nothing is left to guesswork and the manual tries (successfully, we feel) to insure that the user will not make errors due to any poor explanations. The circuit explanation and the schematic diagram allow you to gain an understanding of the principles of analog interfacing.
The Votem is not geared toward a programmer’s use but rather toward the experimenter’s enjoyment. Several applications are described in the manual such as a game paddle or a light detector. Many other uses come quickly to mind; photography (temperature and timing), home energy savings (temperature control), light industry (voltage sensing).
Finally, the cassette interface incorporated on the Votem board allows great scope on tone and volume settings. The “audio out” together with the LED indicator let me know that something was actually happening. A Schmitt trigger in this circuit amplifies the loading signal and reduces noise. This allows you to load a program at a lower volume.
The Votem opens up a whole new world (the real world) of applications for the TS1000/ZX81 user.