Two things occupying me at the moment. I’m mucking around with javascript and web development. I’m also digging through an archive of old BBC Micro software, including a ton of magazine cover disk images from back when that was a thing.
There’s heaps of stuff that make little or no sense without the accompanying magazine. Control programs for hardware projects, or code fragments that are part of a larger tutorial or series. That kind of thing. The bits I enjoy are the tiny BASIC programs that render something cool. Take this one, for example:
10REM > <BasicSave$dir>.KAM_ATRACT
20PRINT"Strange Attractors 1"
30PRINT"The KAM attractor"
40PRINT"By Mike Cook"
50PRINT"A defines the Angle of the orbit in radians"
60REPEAT
70INPUT"Enter a value for A about (1.1 to 1.7) ",A
80MODE0
90PRINT TAB(0,0);"The KAM attractor By Mike Cook"
100sinA=SIN(A)
110cosA=COS(A)
120C%=0
130FOR orbit= 0.1 TO 2.5 STEP 0.05
140C%=C%+1
150REMGCOL 0,C%
160U=orbit/3
170V=orbit/3
180FOR B%= 1 TO 300
190IF ABS(U)>1E6 OR ABS(V)>1E6 THEN GOTO 240
200PLOT 69,(U*640)+640,(V*512)+512
210X=U*cosA-(V-U*U)*sinA
220Y=U*sinA+(V-U*U)*cosA
230U=X:V=Y
240NEXT
250NEXT
260PRINT TAB(0,0)"This is A = ";A;SPC(18)
270PRINT TAB(0,31);
280UNTIL FALSE
I found this one on the April 1991 copy of Micro User. Simple looking thing, but then it goes and does this:
Although it does take a few minutes to get there. I googled KAM attractor and ended up with a bunch of scary looking math papers, and a wikipedia entry. I’ve read the wikipedia entry a couple of times, but I must need another cup of tea because while most of the words appear to be in English, I’m none the wiser at the end of it than I was at the start.
So I’ve got this cool little BASIC program, and I’m trying to figure out javascript, so the consequences were pretty much inevitable.