View source for TWD120

{{Oscilloscope Sidebar 
|manufacturer=Tektronix 
|series=
|model=TWD120 
|summary=100&thinsp;MHz, 100&thinsp;MS/s 8-bit 2-ch digitizer  
|image=twd120 9.jpg 
|caption=Tektronix TWD120 
|introduced=1994 
|discontinued=1995 
|designers= 
|manuals=
* [http://www.ko4bb.com/getsimple/index.php?id=download&file=Tektronix/Tektronix_Miscelaneous/Tektronix_TWD120_Digitizer_Operator_Manual.zip Tektronix TWD 120 Digitizer Instruction Manual (ZIP)]
* [http://www.ko4bb.com/getsimple/index.php?id=download&file=Tektronix/Tektronix_TWD120_Digitizer_Operator_Manual.pdf Tektronix TWD 120 Digitizer Reference Manual (PDF)]
}}
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|067-1436-00 Communications Pod]]

{{BeginSpecs}}
{{SpecGroup|Acquisition}}
{{Spec | Bandwidth | 100&thinsp;MHz (20&thinsp;MHz selectable limit) }}
{{Spec | Sample rate | 2 channels @ 100&thinsp;MS/s each (two digitizers) }}
{{Spec | Resolution | 8&thinsp;bit }}
{{Spec | Record length | 500 to 5000 samples per channel }}
{{Spec | Modes | sample, envelope, average (16 samples), high-resolution, and peak-detect }}

{{SpecGroup | Inputs}}
{{Spec | Deflection | 2&thinsp;mV/div - 99.5&thinsp;mV/div (±1&thinsp;V offset), 100&thinsp;mV/div - 995&thinsp;mV/div (±10&thinsp;V offset), 1&thinsp;V/div - 10&thinsp;V/div (±100&thinsp;V offset) }}
{{Spec | Max. input | ±400&thinsp;V (DC + peak AC) up to 100&thinsp;kHz, derate −20&thinsp;dB/decade up to 3&thinsp;MHz, 13&thinsp;V<sub>p-p</sub> above 3&thinsp;MHz }}
{{Spec | Input impedance | 1&thinsp;MΩ }}

{{SpecGroup | Trigger}}
{{Spec | Trigger modes | edge, error, external and video (NTSC, SECAM, PAL, Sync negative or positive) }}
{{Spec | Trigger Source | CH1, CH2, External }}
{{Spec | Trigger coupling |  AC, noise reject, high frequency reject, low frequency reject }}
{{Spec | Trigger levels | ±12 divisions (CH1, CH2) or up to ±15&thinsp;V (External) }}
{{Spec | Trigger holdoff |  500&thinsp;ns to 10&thinsp;s }}

{{SpecGroup | Misc }}
{{Spec | Interfaces | 
* [[Ultra SCSI II]] (50-pin high density [[SCSI connector]]) for host connection
* [[RS-232 interface]] (DE-9) 
* [[Parallel printer interface]] (DB-25)
}}
{{Spec | Calibrator output | 5&thinsp;V @ 1&thinsp;kHz (1&thinsp;MΩ load) }}
{{Spec | Power | 12−24&thinsp;V<sub>DC</sub>, 30&thinsp;W max }}

{{EndSpecs}}