Physics Demonstrations Changes from Version 1.0 to Version 1.1 Created February 8, 1989 1. The calculation speed has been increased for most of the demonstrations, resulting in less jittery operation on older machines without coprocessors. 2. The required disk space has been reduced by about 6KB. 3. Screen flashing on some monitors and delay when switching between demonstrations has been reduced. 4. Operation under MS-DOS 4.0 has been verified. 5. The layout of the MENU screen has been altered to more closely resemble the DOS 4.0 shell, and additional instructions have been added. 6. The auto-demonstration batch file AUTODEMO.BAT has been revised. 7. Continuous looping of the demonstrations is now done with the command AUTODEMO R rather than LOOPDEMO. 8. Additional instructions have been added to the README.DOC file. 9. README.EXE now chirps when illegal commands are given. 10. Some of the quiz questions have been reworded. 11. Some of the files have been renamed. 12. An additional command has been added to each of the demonstrations to give more user control. 13. An Instructor's Manual is now included with the software. Reaction Time: 14. The dollar bill now drops below the screen briefly before being reset. 15. A reset option has been added to reinitialize the histogram. 16. The histogram now gives a bar graph rather than a line graph. 17. The ordinate of the graph has been labeled. Ballistics Car: 18. Firing of the cannon is now controlled by the user. 19. The maximum speed has been reduced from 16 to 6 m/s. 20. A zero velocity option has been added. 21. The parabolic trajectory of the ball is now shown. The Monkey and the Hunter: 22. The name has been changed to "The Monkey and the Coconut," and the filename has been changed from MONKHUNT to MONKEY. 23. The explanation has been rewritten, deleting references to killing the monkey. 24. Firing of the coconut is now controlled by the user. 25. The maximum speed has been reduced from 320 to 70 m/s. 26. The distance to the monkey has been shortened from 100 to 50 meters. Bowling Ball Pendulum: 27. A single-step option has been added. 28. The colors have been changed on the bar graphs. 29. The profile of a person against the wall has been added. 30. The length of the pendulum now visibly changes. Wilberforce Pendulum: 31. A single-step option has been added. 32. The colors have been changed on the bar graphs. 33. The pendulum bar now has different colors on the two ends to improve the perspective. 44. The oscillation frequency has been reduced and is now independent of the CPU clock speed. 45. Reference marks have been added to the vertical scale to permit quantitative measurement of the oscillation amplitude. Wave Speed on a Rope: 46. An option to change the shape of the wave has been added. 47. The length of the rope has been doubled to slow the animation. 48. The wave speed is now indicated on the screen. 49. The explanation has been modified to provide the answer sought. Flame Pipe: 50. The filename has been changed from FLAMEPIP to FLAME. 51. An option to change the amplitude of the wave has been added. 52. The sound is now turned off automatically when the explanation screen is activated. 53. The explanation has been modified to provide the answer sought. Oscilloscope Waveforms: 54. An option to change the phase of the wave has been added. 55. The waveform displays at nearly three times the previous speed. 56. The explanation has been revised to indicate that the animation is shown in slow motion. Breaking a Beaker with Sound: 57. A reset option now allows the user to reassemble the broken beaker. 58. The beaker now makes a sound when it breaks (when sound is activated). 59. A minor inconsistency in the text cursor appearance has been corrected. Doppler Effect: 60. An option to change the pitch of the sound has been added. 61. A zero speed option has been added. 62. The maximum speed has been reduced from 320 to 60 m/s. 63. A drawing of an observer has been added and labeled. Changes from Version 1.1 to Version 1.2 Created August 30, 1989 1. All individual chain files have been combined into a single (104KB) DEMO.EXE file. 2. The disk space required for the programs has been reduced from 234KB to 130KB, and the number of files reduced from 21 to 6. 3. The user no longer has to copy COMMAND.COM from the DOS disk to the PHYSICS DEMO disk. 4. The delay in switching between demonstrations has been eliminated. 5. The program can now be run with the disk removed from the drive. 6. The auto-cycle sequence is now in a file AUTO.TXT rather than AUTODEMO.BAT. 7. The quiz can now be accessed from the auto-cycle mode. 8. Additional options (- = interrupts the command sequence until the space bar is pressed, $ = displays the disk directory, ! = initiates the quiz program, % = executes commands in AUTO.TXT and . = returns to DOS) now accompany (@ = displays the program logo and ? = initiates help feature) as legal command-line symbols. 9. An R at the end of any command sequence will cause that sequence to repeat forever. 10. The command to enter the auto-cycle mode is changed from AUTODEMO R to DEMO R, and the sequence contained therein has been expanded to include the quiz. 11. The transition from user mode back to auto-cycle mode is now smoother (it picks up where it left off). 12. Exit from the auto-cycle mode is now possible by pressing Ctrl-Home and then Esc (quickly). 13. The help screen scrolls one line less so that the bottom line of one page appears as the top line of the next. 14. The help screen displays an -- End of file README.DOC -- message when the end is reached. 15. The function keys can now be used to scroll the help screen. 16. Pressing when the cursor is over Esc exits from the directory screen. 17. F2 toggles the directory screen on and off. 18. F3 now displays the logo rather than executes a DOS shell. 19. The logo screen and the quiz can now be accessed from computers with only a monochrome text monitor. 20. The mouse driver is now reset every time the program is loaded. 21. A bug in the quiz program grading has been corrected. 22. For quiz grades less than 50%, the message "Your performance was poor" has been changed to "More study is recommended." 23. The format of user-supplied questions in QUIZ.TXT is now not so critical. 24. The number of quiz questions is now limited only by the computer memory. 25. The cursor in the quiz now returns to A after each correct answer. 26. Incomplete erasure of the Ballistics Car screen has been corrected. 27. A typographical error in the Flame Pipe explanation has been corrected. 28. Error trapping (wrong hardware, missing disk files) has been improved. 29. A problem with the computer locking up at midnight has been corrected. 30. The program author's address has been changed from a home address to a university affiliation. 31. The information for ordering additional related materials has been reworded on the logo screen. 32. The documentation (README.DOC) has been updated to reflect the above changes. Changes from Version 1.2 to Version 1.21 Created October 10, 1991 1. The version number has been changed from 1.2 to 1.21. 2. The copyright date has been changed from 1989 to 1991. 3. The program has been compiled with a more recent verion (1.1) of the Turbo BASIC compiler. 4. A problem with the menu cursor not returning to its proper position after exiting the Reaction Time demo has been corrected. 5. The README.DOC file can now contain up to 200 lines of text rather than the previous 120 lines. 6. The Help screen text now appears in white on blue. 7. Certain illegal commands now produce a chirp. 8. The Num Lock key status is tested before starting the program, turned off during operation, and restored upon exit. 9. The cursor position on the menu screen is remembered and restored after a demonstration is run. 10. When the program is launched with certain commands such as DEMO,R the computer no longer freezes up. 11. now replicates the function of the key. 12. Zero is now an allowed delay in the command string. 13. The README.TXT and README.DOC files have been updated. 14. The QUIZ.TXT file has been reworded to agree with the format in the User's manual. Changes from Version 1.21 to Version 1.22 Created February 27, 1993 1. The version number has been changed from 1.21 to 1.22. 2. The copyright date has been changed from 1991 to 1993. 3. The program has been compiled with PowerBASIC 3.0, which increases the speed and makes a coprocessor completely unnecessary. 4. A problem with the keyboard buffer occasionally overflowing and hanging the machine when the sound is functioning has been fixed. 5. The Wilberforce pendulum motion is now smoother on fast computers. 6. The oscilloscope waveform gives a more steady display on fast computers. 7. The screen now fades (VGA) or dissolves (EGA, CGA) between demos in museum mode in response to a semicolon (;) in the command sequence. 8. The key now allows one to advance promptly through the demonstrations while in museum mode. 9. Background color changes are now remembered from one demo to the next except when in museum mode. 10. The quiz is graded differently so that a skipped question is counted as wrong rather than right. 11. The auto mode now supports script files supplied by the user when launched from DOS with a command such as DEMO (MYSCRIPT.TXT). 12. A minor correction was made in the ballistics car explanation. 13. Global error trapping has been improved.