Program used to generate schematics?

[gomerpyle]

http://img607.imageshack.us/img607/8638/schematics.jpg

Could someone tell me what software was used to make these? I need to create similar schematics of a DAQ system but don't know the name of the program used to do it. Thanks.

 

[Simon Bridge]

I doubt there is any way to tell - it is very generic.
I could probably draw something close to those using the fig environment in LaTeX even.
There are a lot of schematic and chart-building editors out there from xfig to via and beyond. Pick one.

 

[jhae2.718]

Eagle might work.

Edit: the image kind of looks like AutoCAD to me.