The Tektronix TWD 120 Digitizer allows a Windows PC to be used as a digital storage oscilloscope. It is rated at 100 MHz, has two input channels and an external trigger input. It connects to the host PC via a SCSI bus.
The TWD 120 is about the size of a laptop, and was supplied with a soft case. It was intended to be used in conjunction with a laptop running Windows 3.1, and was apparently manufactured for GE for use by medical device field technicians.
The Adaptec ASPI SCSI driver is required for the software to communicate with the digitizer. SCSI configuration can be tricky.
Firmware is updated using the 067-1436-00 Communications Pod
|— Acquisition —|
|Bandwidth||100 MHz (20 MHz selectable limit)|
|Sample rate||2 channels @ 100 MS/s each (two digitizers)|
|Record length||500 to 5000 samples per channel|
|Modes||sample, envelope, average (16 samples), high-resolution, and peak-detect|
|— Inputs —|
|Deflection||2 mV/div - 99.5 mV/div (±1 V offset), 100 mV/div - 995 mV/div (±10 V offset), 1 V/div - 10 V/div (±100 V offset)|
|Max. input||±400 V (DC + peak AC) up to 100 kHz, derate −20 dB/decade up to 3 MHz, 13 Vp-p above 3 MHz|
|Input impedance||1 MΩ|
|— Trigger —|
|Trigger modes||edge, error, external and video (NTSC, SECAM, PAL, Sync negative or positive)|
|Trigger Source||CH1, CH2, External|
|Trigger coupling||AC, noise reject, high frequency reject, low frequency reject|
|Trigger levels||±12 divisions (CH1, CH2) or up to ±15 V (External)|
|Trigger holdoff||500 ns to 10 s|
|— Misc —|
|Calibrator output||5 V @ 1 kHz (1 MΩ load)|
|Power||12−24 VDC, 30 W max|
- More info, including good information on SCSI configuration and work arounds for using later versions of Windows
- EEVblog teardown comments and pictures