Re: Mental challenge: the rainbow

[mmphosis <mmphosis@yahoo.com>]

On Feb 5, 7:25 pm, "Marc S. Ressl" <mre...@gmail.com> wrote:
> Hello everyone,
>
> This code was posted by mmphosis at comp.sys.apple2.programmer:
>
>  10 A = 9200
>  20 B = 13136 + 32
>  30 C = 100
>  40  TEXT : HOME
>  50 DATA 173,87,192,173,83,192,173,84,192,173,80,192,208,251
>  55 DATA 173,86,192,160,22,136,208,253,234,173,87,192,76,9,3
>  60  FOR I = 768 TO 796
>  70  READ N: POKE I,N
>  80  NEXT
>  100  HGR : POKE  - 16302,0
>  110  HCOLOR= 4
>  120  HPLOT 0,0: CALL 62454
>  130  HCOLOR= 2
>  140  HPLOT 0,63 TO 279,63
>  150  HPLOT 0,62 TO 279,62
>  160  HCOLOR= 6
>  170  HPLOT 0,61 TO 279,61
>  180  HPLOT 0,60 TO 279,60
>  190  HCOLOR= 1
>  200  HPLOT 0,59 TO 279,59
>  210  HPLOT 0,58 TO 279,58
>  220  HCOLOR= 5
>  230  HPLOT 0,55 TO 279,55
>  240  HPLOT 0,54 TO 279,54
>  250  HCOLOR= 0
>  260  HPLOT 0,123 TO C,123
>  261  HPLOT 0,122 TO C,122
>  262  HPLOT 0,119 TO C,119
>  263  HPLOT 0,118 TO C,118
>  270  COLOR= 0
>  280  FOR I = 0 TO 39
>  290  VLIN 0,39 AT I
>  300  NEXT
>  310  COLOR= 13
>  320  HLIN 0,39 AT 14
>  330  FOR I = 0 TO 7
>  340  POKE A + I,0
>  345  POKE B + I,0
>  350  NEXT
>  360  COLOR= 1
>  370  HLIN 0,39 AT 13
>  380  VTAB 21
>  390  PRINT  TAB( 16)"RAINBOW"
>  400  PRINT : PRINT "MIXED GRAPHICS (HI-RES/COLOR)"
>  500  CALL 768
>
> I've re-factorized the timing code in OpenEmulator, and the rainbow is
> showing. My problem is the "special" lines are flickering at the
> beginning.
>
> I have checked the code, and it seems it should be flickering (the
> loop waits for a non-zero byte on the floating bus), but could
> somebody with a real Apple II or II plus check?
>
> Thanks a lot,
>
> Marc.-