Here is the Ninth example of the next release of PortablE:
Example 9: StarsZ.e

After writing the first "stars" example, I got to wondering how a lowly A500 could manage to "zoom into" stars...  After some fiddling I came-up with an algorithm which has low memory & CPU usage, and only uses integer maths.  So it could quite plausibly be the same algorithm as used by some A500 demos (albiet in E not 68k assembler).

This example shows stars moving out of the screen (in the Z plane), in 92 lines of code.