If you’re a fan of vintage electronics and DIY tinkering, you’ll find this teardown by [Thomas Scherrer] fascinating. In a recent video, he delves into a rare piece of equipment: the Data Lab Transient Recorder DL 901. This device looks like a classic one-channel oscilloscope, complete with all the knobs and settings you’d expect.
The DL 901, made by Data Laboratories Ltd., is a mystery even to [Thomas], who couldn’t find any documentation online. From the DC offset and trigger settings to the sweep time controls, the DL 901 is equipped to handle slow, high-resolution analog-to-digital conversion. The circuitry includes TTL chips and a PMI DAAC 100, a 10-bit digital-to-analog converter. [Thomas] speculates it uses a successive approximation technique for analog-to-digital conversion—a perfect blend of analog finesse and digital processing for its time.
Despite its intriguing features, the DL 901 suffers from a non-responsive analog input system, limiting the teardown to a partial exploration. For those who enjoyed past Hackaday articles on oscilloscope teardowns and analog tech, this one is a treat. Watch the video to see more details and the full process of uncovering this vintage device’s secrets.
I built my own digital sampler with almost the same functionality as this one from scratch in 1979. I just published its contents in a Hackaday project, so this teardown explanation is deeply moving. At a time when digital oscilloscopes were not available as they are today, such a device was much needed as a function that could be attached externally to an analog oscilloscope to allow observation of transient phenomena.
Was that not a gpib ieee488 connector on the back? wonder if that would return anything useful?
I bet it can, just what is it? I have a HP 3478A with hpbib (what HP originally
designed that eventually turned into GPIB) and yes its electrically fine but its not like using IEEEEEEEEEEEEE488 standards. On a more modern device one might use SCPI commands to return values, but on this if you want to read it, it sends the display register data corresponding to what LCD segments are set as on or off, and its left to you to figure out to a point :)
In that case it wasn’t hard to write a little C# application cause the documentation was available, but its not as simple as “MEAS:VOLT:DC?”
SCPI (skippy yay!) was after 488 came about around 1990, my meter debuted in 1983
I also have a HP34401A which came out in 91 and lasted at least in legacy modes up until about 7? ish years ago before keysight dropped the legacy modes off their bench / rack mount meters its dead simple to use thanks to SCPI (along with every other maker of the last 30 years) … just off the top of my head in pseudo code
SYS:REM
CONF:VOLT:DC
MEAS VOLT?
and it will return a scientific notation value in plain ascii over RS232 or 488 … we have a dozen of these things floating around work cause for the last 15 years they were almost free compared to modern versions, and any computer made within the last 60 years can convert SN to DEC and shove it into a database faster than a fly blinks lol
DAC100! PMI was bought by Analog Devices in about 1990. The DAC100 is still sold in some military and aerospace applications.
I to have had issues with old school 488 interfaces.