These run reliably under Windows 95 if the following precautions are taken

Download both the executable file and the batch file. (The batch launches the executable.)
Save both in a directory whose name is 8 characters or less.
Double-click the batch file (not the executable) to launch the DOS program.

  Stopwatch program. (Does simple keyboard timing of events)
[Executable Stwatch.exe ]   [Batch stwatch.bat ]

  Light refraction simulation. (Refraction at plane surface, two draggable sources, which give an object. Adjustable indices of refraction. Shows image formation, illustrates total internal reflection schematically.)
[Executable Refrac5.exe ]   [Batch refrac5.bat ]

  Lenses and Mirrors. (Draggable light source, two lenses or one mirror. Illustrates real and virtual images, virtual objects. Uses simple lens equation to locate image. Large array of rays can be drawn.)
[Executable Lensmir2.exe ]   [Batch lensmir2.bat ]

  Grating simulation. (Shows waves coming into grating in step. Slider selects output angle and user can see if waves are in step at that angle. Grayscale intensity pattern is available. Slider selects up to 6 slits.)
[Executable Gratinga.exe ]   [Batch gratinga.bat ]

  Wave interference simulation. (An extract of software marketed by Physics Academic Software. It illustrates what a phasor represents. It shows one and two phasor interference. It shows grayscale patterns of 2-source interference and ties path difference (a bar graph shows how much path difference) to a phasor diagram, and to the grayscale plot. Advanced features are not enabled.)
Problem statements for the wave interference simulation (21 problems).
Problem solutions for the wave interference simulation.
[Executable waveintx.exe ]   [Batch waveintx.bat ]

  Particle motion in magnetic fields (Particle moves in the field of one or two magnetic dipoles. Will simulate magnetic bottles, Van Allen belts, etc.)
[Executable Diporb.exe ]   [Batch diporb.bat ]

  Boltzmann engine. (User initially selects populations of lowest 3 states of a collection of harmonic oscillators. Program exchanges + or - 1 or 2 in nearby states, keeping total energy the same, and moves in the direction of increasing entropy. As time goes on, the populations of the lowest states (lowest 9 are shown) approach the boltzmann distribution.)
[Executable boltzmna.exe ]   [Batch boltzmna.bat ]

  Driven inverted pendulum. (User controls frequency, amplitude of vertical drive for an inverted pendulum. At a high enough combination of amplitude and frequency, and the right phasing, the inverted pendulum will oscillate upside down, drive from below.)
[Executable invpend.EXE ]   [Batch invpend.bat ]

  Rigid body motion under no torque. (This shows the motion of a rigid body whose dimensions are specified by the user, and whose initial angular momenta are also user-specified. It shows the orbit in angular momentum space as the intersection of an ellipsoid and a sphere, letting one see where stable motions will occur. It also animates the motion of the body itself, showing both angular momentum vector L and angular velocity. These two vectors are simultaneously represented in xyz space where L is constant, and 123 (body-axis space).)
[Executable rigid.EXE ]   [Batch rigid.bat ]

Geiger tube analysis program. Works with input via parallel port. TTL signal is fed to a D latch whose input is tied high. A TTL pulse clocks the high through to the output. After the count is recorded, the latch is reset. Program will display graph of counts per second in 'counts' mode. It also has a 'histogram' mode in which it displays a histogram of occurrences vs count. A poisson distribution can be superimposed on this graph and adjusted. The program will also display intervals between counts (of interest for dead time, and the 'interval distribution'). Finally, there is a 'Program' mode, in which one may program a set of data, for example 60 readings at 1 min each, then 50 readings at 30 min each.[Executable geiger.EXE ]   [Batch geiger.bat ]

PN junction simulation. This shows the exponential distribution of electrons in the conduction band on the n-side of the junction, and the 'hill' of potential energy between n-side and p-side of the junction. There are sliders for applied bias to the junction, and for temperature. When the slider for applied bias is dragged, one sees the hill size change. The number of electrons able to surmount the hill.is shown in a different color, and changes as the hill changes. There is also an I-V curve shown, so a student can see the hill change, the number of electrons 'up the hill' change, and watch the progress of the I-V curve.[Executable pnjctn.exe]   [Batch pnjctn.bat]

 Decay simulation program simulating growth and decay of silver half lives Decaypm1.exe. Accompanying file Egavga.bgi.

Magnetic field program. Takes data from Vernier magnetic field probe through the BIB box. [Executable magplot.exe] [Batch magplot.bat]