Correcting Graphics on Printers

Those members who have recently purchased a printed may be dismayed to learn that circles may print egg shaped. There is no correction for the 2068 command CIRCLE but use a formula and you can solve the problem. Use this formula to generate a controlled circle on the 2068

10FOR I=0 TO 2*PI STEP PI/200
20PLOT 125+80*COS I, 80+80*SIN I
30NEXT I

On my 2040 printer the image is 63 mm high x 51 mm wide. This makes a ratio of 1.24 so COS needs to be 1.24 times wider. Just change to 1.24*80*COS I to print a practically true circle. You could also use 80/1.24*SIN and have 51 mm circle.

A similar problem may exist with the TV screen and can be corrected the same way. My TV has an image 15% higher than wide.