^{}Difference between Decimal BASIC and Microsoft BASIC

**Graphics**

**1. Coordinates**

A coordinate system is introduced by a SET WINDOW statement.

SET WINDOW has four parameters left, right, bottom, top.

That is, first two parameters are the range of x-coordinate, the rest are the range of y-coordinate.

`SET WINDOW`

x1,x2,y1,y2

correspond to WINDOW (x1,y2)-(x2,y1) on Quick BASIC.

The positive direction of y-axis is upward, though a user can set the coordinate system y-axis downward.

Thus,`WINDOW (x1,y1)-(x2,y2)`

can be replaced by

`SET WINDOW x1,x2,y2,y1`

If you want to set the pane size 640×480, execute an original statement

` SET BITMAP SIZE 640,480`

**2. Points and lines**

In most cases, re-written can be done by

replacing `PSET(x,y) `

by `PLOT x,y`

` LINE (x1,y1)-(x2,y2) `

by `PLOT x1,y1 ; x2,y2`

` LINE -(x,y) `

by ` PLOT x,y; `

`PLOT x,y; `

means `LINE (x,y)- `

in the notation style of Microsoft BASIC.

The PLOT x,y; executed first does not draw a line except the point.

That is, the PLOT x,y; executed first determines the initial point of a line graph.

To terminate a line graph, add a PLOT statement that has no arguments.

Refer to Introduction to BASIC Curves and Graphs
Foundation of Graphics