1               / Kaleidoscope program for the VC8E/VR14 scope.
   2               / Based on suggestions from page 6-19 of the Small
   3               / Computer Handbook, 1973.
   4               
   5               / The advice given is to experiment with settings
   6               / of the switch register bit positions 9, 10 and 11,
   7               / leaving all higher bits zero.  The advice is good;
   8               / this is a nice "screen saver" for non-storage
   9               / scopes.
  10               
  11               DISD=   6052
  12               DILX=   6053
  13               DILY=   6054
  14               DIXY=   6055
  15               
  16                       *200
  17 000200  1224  START,  TAD     Y
  18 000201  4225          JMS     SCALE
  19 000202  7040          CMA
  20 000203  1223          TAD     X
  21 000204  3223          DCA     X       / X = X - SCALE(Y)
  22 000205  1223          TAD     X
  23 000206  6053          DILX
  24 000207  4225          JMS     SCALE
  25 000210  1224          TAD     Y
  26 000211  6054          DILY
  27 000212  6052          DISD
  28 000213  5212          JMP     .-1
  29 000214  6055          DIXY
  30 000215  3224          DCA     Y       / Y = Y - SCALE(X)
  31 000216  6031          KSF             / VRS: Key struck?
  32 000217  5200          JMP     START
  33 000220  6032          KCC             / VRS: Toss the character
  34 000221  5622          JMP I .+1       / VRS: Yes, return to OS/8
  35 000222  7600          7600
  36 000223  3777  X,      3777            / any initial value works, but
  37 000224  0006  Y,      6               / 0,0 is least interesting.
  38               
  39               / Divide AC by 2**SR
  40 000225  0000  SCALE,  .-.
  41 000226  3242          DCA     TEM
  42 000227  7404          OSR
  43 000230  7041          CIA
  44 000231  3243          DCA     C
  45 000232  1242          TAD     TEM
  46 000233  7100          CLL
  47 000234  7510          SPA
  48 000235  7020          CML
  49 000236  7010          RAR             / Arithmetic right shift
  50 000237  2243          ISZ     C
  51 000240  5233          JMP     .-5
  52 000241  5625          JMP I   SCALE
  53 000242  0000  TEM,    .-.
  54 000243  0000  C,      .-.
  55               $

C       0243
DILX    6053
DILY    6054
DISD    6052
DIXY    6055
SCALE   0225
START   0200
TEM     0242
X       0223
Y       0224