25. Meter Reader


General Description

This program has been designed to help students read electrical meters correctly. Its vivid graphical display and lucid instructions mean that, after initial preparation, this program can be used unsupervised.

Detailed Description

   Lines 100-250 Main Program.
   270-460 PROCscreen: Selects colours, defines graphics and text windows using VDU24,28.
   480-900 PROCscale: Draws meter and numbers scale using VDU29.
   920-1070 PROCranges: Choices of f.s.d. and subdivisions is read into RANGE array from DATA lines 990-1020. Lines 1040 and 1050 randomly choose values of SF and SD%.
   1090-1250 PROCpointer: Draws pointer. 1170 calculates number of subdivisions on chosen scale and 1180 converts this into angle of deviation.
   1270-1520 PROCuser: This part of the program deals with computer-user interaction.
   1540-1670 PROCtitle: Uses teletext Mode 7 to produce double height characters.
   1690-1930 PROCinfo: Provides the program information.
   1950-1990 This section generates error message, and offers options.

Educational Notes

In the classroom this program could be used in conjunction with a real meter to teach scale reading. It also lends itself to being used in a remedial situation with small groups of students who either missed or misunderstood the original lesson.
   To modify the program to suit particular meters, just change the DATA values in PROCrange.