XYdisp measures just the X- and Y-voltage output by your measurement setup. It does not communicate with or has any knowledge of what instruments you connect. It is therefore a simple display program you could easily adapt to your own needs without having to modify your equipment other than perhaps converting output voltages to be between 0 and 5V.
XYdisp runs on any PC from an old 386 to a modern Pentium. It runs under DOS and uses the PC's parallel port, so it will not run under NT or XP. It uses a simple parallel-port one-chip I2C interface.
On the I2C bus is a Philips PCF9851 ADC/DAC chip. This has a four-channel 8-bit ADC and one 8-bit DAC.
I use only the first two ADC channels in the program.
The first channel measures the X-signal or horizontal voltage, which is generated in my
The second channel measures the log-detector's response, in my case the log-output voltage of my microwattmeter.
XYdisp is particularly suited for sweepers with a triangle-shaped sweep-voltage as there is no problem with the 'back-trace' (?) as with a sawtooth shaped sweep-voltage. However, you could modify XYdisp to use a third channel to monitor a 'back-trace' signal to suppress this in the display.
The result of XYdisp may look like this:
Here is a zip-file which contains the program executable, the program source and a user-manual with schematics.
Send your comments (email address is on my home-page)