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 00200 1224 START,  TAD     Y
  18 00201 4225         JMS     SCALE
  19 00202 7040         CMA
  20 00203 1223         TAD     X
  21 00204 3223         DCA     X       / X = X - SCALE(Y)
  22 00205 1223         TAD     X
  23 00206 6053         DILX
  24 00207 4225         JMS     SCALE
  25 00210 1224         TAD     Y
  26 00211 6054         DILY
  27 00212 6052         DISD
  28 00213 5212         JMP     .-1
  29 00214 6055         DIXY
  30 00215 3224         DCA     Y       / Y = Y - SCALE(X)
  31 00216 6031         KSF             / VRS: Key struck?
  32 00217 5200         JMP     START
  33 00220 6032         KCC             / VRS: Toss the character
  34 00221 5622         JMP I .+1       / VRS: Yes, return to OS/8
  35 00222 7600         7600
  36 00223 3777 X,      3777            / any initial value works, but
  37 00224 0006 Y,      6               / 0,0 is least interesting.
  38            
  39            / Divide AC by 2**SR
  40 00225 0000 SCALE,  .-.
  41 00226 3242         DCA     TEM
  42 00227 7404         OSR
  43 00230 7041         CIA
  44 00231 3243         DCA     C
  45 00232 1242         TAD     TEM
  46 00233 7100         CLL
  47 00234 7510         SPA
  48 00235 7020         CML
  49 00236 7010         RAR             / Arithmetic right shift
  50 00237 2243         ISZ     C
  51 00240 5233         JMP     .-5
  52 00241 5625         JMP I   SCALE
  53 00242 0000 TEM,    .-.
  54 00243 0000 C,      .-.
  55            $

C       0243
DILX    6053
DILY    6054
DISD    6052
DIXY    6055
SCALE   0225
START   0200
TEM     0242
X       0223
Y       0224