This is one from my archives.
They're in such a mess. No cataloging at all.
My early ideas came from imitating effects I'd seen.
Had to find this one, when I noticed the DBF home page.
open window 640,512
title=1
go=1
m=1
go1=64
m1=1
stars=250
ang=pi/180
dir=6
dim x(stars),y(stars),z(stars),m(stars),s(stars)
for a=1 to stars
s(a)=ran(.01)
x(a)=ran(360) rem degrees used of circle
z(a)=ran(410) rem distance from center
next a
repeat
setdrawbuf vm
vm=1-vm
setdispbuf vm
clear window
for a=1 to stars
m(a)=m(a)+s(a)
z(a)=z(a)+m(a)
if z(a)>410 then
s(a)=ran(.01)
m(a)=0
z(a)=0
x(a)=ran(360)
endif
setrgb 1,256,256,256
fill circle cos(dir*ang*x(a))*z(a)+320,sin(dir*ang*x(a))*z(a)+256,m(a)*1.5
next a
go=go+m
if go<1 m=1
if go>128 m=-1
if go>128 title=title+1
if title>13 title=1
setrgb 1,256-(go*2),256-(go*2),256-(go*2)
if title=1 text 210,260," SPACE . . ."
if title=2 text 210,260," THE FINAL FRONTIER"
if title=3 text 210,260," THESE ARE THE"
if title=4 text 210,260," CONTINUING VOYAGES"
if title=5 text 210,260," OF BIKEMADNESS."
if title=6 text 210,260," HIS MISSION,"
if title=7 text 210,260," AS HE IS ATTEMPTING IT,"
if title=8 text 210,260," IS TO UNDERSTAND ENOUGH"
if title=9 text 210,260," CODE AND PROGRAMMIMG"
if title=10 text 210,260," TO REALISE MOST"
if title=11 text 210,260," OF HIS IDEAS."
if title=12 text 210,260," TO FRUITION AND COMPLETION,"
if title=13 text 210,260,"WITH NOT TOO MUCH FRUSTRATION."
until (1=0)
I always liked the star field effect.