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  • Overview
  • Features
  • Requirements
  • FAQs
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Serial Response Box™ Overview

This product has been discontinued


The Serial Response Box features a 0 millisecond debounce period. This is something that simply cannot be achieved from a standard keyboard!


PST has engineered the Serial Response Box so that the response is time stamped and then the signal is verified for accuracy.


A standard keyboard verifies the accuracy of the signal before the response is time stamped. The problem of variable debounce periods found on keyboards is solved with the Serial Response Box!


Best of all, the Serial Response Box connects directly to the PC via the serial port! No additional hardware is required.


The Serial Response Box consists of the following items:

  • 1 Serial Response Box with textured scratch resistant metal case
  • 5 Lamps
  • 5 Sample lamp covers (Red, White, Blue, Green and Yellow)
  • 5 Keys with over 150 customized key labels - no longer included
  • 1 Microphone
  • 1 Voice key with programmable trip level
  • 1 RS-232 Cable Assembly 6 foot, DB9 Female to DB25 Male
  • 1 15V DC Power Supply (100 - 240VAC input)
  • 1 40-pin IDC expansion cable with header (to expand the number of keys and lamps via the expansion port)
  • Refresh detector circuitry (for use with PST Refresh Detector) - DISCONTINUED


The following accessories are sold separately:


  • Custom Expansion Kit - DISCONTINUED
    • Eight drill-mount switches
    • Eight switch caps
    • Five lamps
    • Five lamp lenses
    • One prototyping board
    • One Interface cable
    • Drill bits for switches and lamps
    • Mounting hardware and case (10" x 8.03" x 2.70")
  • Foot Pedal - DISCONTINUED



Serial Response Box Custom Expansion Kit - DISCONTINUED




Serial Response Box Foot Pedal - DISCONTINUED



For Serial Response Box Serial to USB converter information, read KB article 1835.



SRBOX Tutorial (194KB zip file) Includes the Tutorial.pdf, Tutorial: Modify Tutorial.es to accept Serial Response Box input, along with the Tutorial.es file.


SRBOX Sample For E-Prime (547KB zip file) An E-Studio experiment testing SRBOX functionality and illustrating use of the SRBOX with E-Prime.


This product is intended for research use only.







Serial Response Box™ Features

This product has been discontinued


Refresh Detector System - DISCONTINUED

The Serial Response Box includes a Refresh Detector System which is used to determine how many times a second the computer screen is redrawn or refreshed.



The Serial Response Box features 5 keys. Single key presses, key presses and releases as well as n-key rollover responses (e.g., collect information about key responses which overlap in time) are supported. The keys can be labeled in accordance with your experiment. Place a label inside the keycaps of the Serial Response Box's 5 keys. PST ships 5 sheets of labels with every Serial Response Box ordered.



The Serial Response Box features 5 lamps. Samples of 5 colored lamp covers are also included with the Serial Response Box. The lamp covers are easily interchangeable.


Voice Key The Serial Response Box also features an integrated voice key. The voice key allows you to collect vocal latencies with confidence. This is not to be confused with the ability to record actual vocal responses. To record vocal responses we suggest the use of an external recorder. The voice key features both a hardware volume control and sensitivity control via E-Prime®.







Serial Response Box™ Requirements

This product has been discontinued


    • Windows compatible PC (Win98SE or later)
    • Serial Port or Compatible USB to Serial Converter
    • E-Prime v1.x or higher
    • 128 MB RAM
    • 32-bit or 64-bit machine


Serial Response Box™ FAQs

This product has been discontinued


Q: Why do I need the Refresh Detector System?

A: The PST Refresh Detector System was designed for use in conjunction with the Serial Response Box and E-Prime. It is included with the purchase of the Serial Response Box. It is used to determine how many times per second the computer screen is redrawn or refreshed. The PST Refresh Detector System is quite useful for experiments with very brief display durations (i.e. under 100 milliseconds). It is critical that you take your hardware (as it relates to your experimental design and stimulus presentation) into consideration.


The PST Refresh Detector System allows the researcher to find out the precise timing of their screen’s refresh rate (or redraw time).


Precise timing information of screen refresh is crucial to experiments that use very short display times. For example: if you wanted to run an experiment in which the subject is presented with a word on the computer screen for less than 30 milliseconds, it would be very important to know if your monitor could refresh a screen that quickly. That is, you must determine if your computer hardware is capable of presenting the word and then erasing or masking the word (two screen updates) within 30 milliseconds.


Features at a glance:

  • The PST Refresh Detector System is a phototransistor that mounts to your computer screen using suction cups and a mounting bracket. It connects to a special port on the back of the Serial Response Box.
  • When placed over a brightly lit section of the monitor screen, the phototransistor pulses each time the screen is refreshed. A typical computer screen is refreshed (redrawn) between 60 and 90 times every second.
  • The monitor’s refresh rate is a function of the brand of the monitor, the type of video card driving the monitor, the mode (graphics or text) and the current video resolution the computer is using.
  • Refresh rates are normally reported in the video card and monitor documentation in hertz (Hz), (e.g., a refresh rate of 60 Hz equates to 16.67 msec per refresh).
  • The Refresh Detector System also includes a set of o-scope leads which allow you to examine the wave form generated by the phototransistor directly with external hardware (i.e., oscilloscope).


Testing of the Refresh Detector system should be performed in low ambient light conditions. Bright background light can interfere with the Refresh Detector and cause erroneous readings.







Serial Response Box™ Pricing

This product has been discontinued

Please email us at sales@pstnet.com for further information.



Price (US Dollars)

Serial Response Box no longer includes the Refresh Detector System - DISCONTINUED


Custom Expansion Kit - DISCONTINUED





All prices are provided in US funds. Prices do not include the cost of shipping and handling and are subject to change without notice.


Serial Response Box™ Support

For technical support please visit our Product Service and Support Website.

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