Remember the Tandy Model 100/102 "laptop" from the early to mid 80s? I got ahold of a couple and have one of them in my travel bag as a terminal for an APRS/portable packet setup. That leaves one to experiment with...

There's a fan site - 'Club100' - where lots of archived information (including a Model 100 monthly magazine) can be found. Looking through those archives, I came across an ad for an RS-232-controlled I/O device which could be commanded via simple BASIC program sequences. Perfect for the Model 100 and a lot of other simple serial-port interfacing applications. Finding that original product (made by Sisa) proved impossible, so I started looking for modern-day alternatives.

Ontrak gave me what I needed in spades. They offer a comprehensive line of analog/digital data acquisition devices with USB and RS-232/485 interfaces. Some of these are capable of controlling stepper motors and offer a pulse-width-modulated output.

They can be daisy chained. One ringport to rule them all. Ideal for a device with only one serial port, such as the Model 100/102.

I managed to grab an ADR2000 and an ADR2200 as gub'mint surplus. An ADR2100 (stepper/PWM capabilities) came from yet another eBay vendor. Taken together, all these together have gotten some creative juices flowing. The event counter can be tied to an anemometer which uses a Hall Effect sensor and we have wind speed readout with a little programming. A 360-degree potentiometer coupled to a wind vane and interfaced to one of the analog input ports gives us wind direction, and an LM335 gives us temperature. If I can find a barometric pressure sensor which works with +5VDC applied and is affordable for mere mortals, barometric pressure can be measured.


The analog I/O and stepper motor controller functions of the ADR2100 could be incorporated into a remote antenna tuner. An az-el rotor readout for satellite or moonbounce work can be implemented with a pair of 360-degree potentiometers.

Multi-axis CNC readouts and control is possible. For that matter, one could implement a complete PLC with these modules.

Anyone ever play with Ontrak's, ICS or similar units?