A digital volt meter that displays voltages on your TV screen, with both giant digits and an analogue bar display. Maximum and minimum peaks are displayed, too. Serial output for use as a data logger in conjunction with your PC.
http://www.riccibitti.com/dvm.htm
What is an oscilloscope, what can you do with it, and how does it work? This section answers these fundamental questions.
http://www.cs.tcd.ie/courses/baict/bac/jf/labs/scope/oscilloscope.html
with ADC0820 connected to the printer parallel port
http://www.geocities.com/lptscope/
adapter attached to a TV set that changes it to low frequency oscilloscope
http://www.intio.or.jp/jf10zl/tvosc.htm
http://www.web-ee.com/Electronic-Projects/projects/telescope/index.shtml
used to make crysral filter
http://www.intio.or.jp/jf10zl/csg.htm
inexpensive and quick way to check the timebase speeds and linearity in vintage oscilloscopes
http://www.edn.com/archives/1997/042497/09di_05.htm
Use your TV screen as a basic oscilloscope display, requires no modifications to the television, bandwidth is limited to 20KHz
http://www.electronic-projects.net/Electronic-Projects/projects/telescope/index.shtml