First public commit.

lenser/apple/viewer/awyt.i

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+; Shared display-duration epilogue for the Apple II viewers (HGR already on).
+; WAITMODE 0 forever, 1 until a key, 2 about WAITSECS seconds.
+; key and seconds exit to Applesoft BASIC ($E000 cold start), a real prompt with
+; no DOS needed.  The II and II+ have no timer, so seconds is a calibrated delay
+; loop near 1 MHz.  WAITSECS is clamped to 255 by the assembler.
+
+#if WAITMODE == 0
+awhang:
+        jmp awhang
+#endif
+
+#if WAITMODE == 1
+awhang:
+        lda $c000               ; keyboard; bit7 set = a key is down
+        bpl awhang
+        bit $c010               ; clear strobe
+        lda $c051               ; switch to text so the BASIC prompt is visible
+        lda $c054               ; page 1
+        jmp $e000               ; Applesoft cold start
+#endif
+
+#if WAITMODE == 2
+        lda #WAITSECS
+        sta $fd                 ; seconds remaining
+aw_o:
+        lda #$03                ; ~1 second = 3 * (256*256 inner) at ~1 MHz
+        sta $fc
+aw_m:
+        ldx #$00
+aw_x:
+        ldy #$00
+aw_y:
+        dey
+        bne aw_y
+        dex
+        bne aw_x
+        dec $fc
+        bne aw_m
+        dec $fd
+        bne aw_o
+        lda $c051               ; switch to text so the BASIC prompt is visible
+        lda $c054               ; page 1
+        jmp $e000               ; Applesoft cold start
+#endif