Ported the C64 screensavers to the Apple2. This turned out to be quite simple as they were based on a 40x25 block pseudo-graphics mode based on coloring inverse blanks. The Apple2 has a native 40x24(resp.48) block graphics mode.
diff --git a/contiki-apple2/apps/ssfire.c b/contiki-apple2/apps/ssfire.c
new file mode 100644
index 0000000..574a652
--- /dev/null
+++ b/contiki-apple2/apps/ssfire.c
@@ -0,0 +1,170 @@
+/*
+ * Copyright (c) 2002-2004, Adam Dunkels.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following
+ * disclaimer in the documentation and/or other materials provided
+ * with the distribution.
+ * 3. The name of the author may not be used to endorse or promote
+ * products derived from this software without specific prior
+ * written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
+ * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
+ * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * This file is part of the Contiki desktop environment
+ *
+ * $Id: ssfire.c,v 1.1 2005/05/12 21:12:43 oliverschmidt Exp $
+ *
+ */
+
+#include <stdlib.h>
+
+#include "ctk.h"
+#include "ctk-draw.h"
+#include "ctk-mouse.h"
+#include "ek.h"
+#include "loader.h"
+
+
+/*static DISPATCHER_SIGHANDLER(ssfire_sighandler, s, data);
+static void ssfire_idle(void);
+static struct dispatcher_proc p =
+ {DISPATCHER_PROC("Fire screensaver", ssfire_idle,
+ ssfire_sighandler,
+ NULL)};
+ static ek_id_t id;*/
+
+EK_EVENTHANDLER(ssfire_eventhandler, ev, data);
+EK_POLLHANDLER(ssfire_pollhandler);
+EK_PROCESS(p, "Fire screensaver", EK_PRIO_LOWEST,
+ ssfire_eventhandler, ssfire_pollhandler, NULL);
+static ek_id_t id = EK_ID_NONE;
+
+static unsigned char flames[8*17];
+
+static const unsigned char flamecolors[16] =
+ {0x00, 0x00, 0x00, 0x11, 0x99, 0xDD, 0xFF, 0xFF,
+ 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
+
+static unsigned char *flameptr;
+static unsigned char x, y;
+
+
+/*-----------------------------------------------------------------------------------*/
+LOADER_INIT_FUNC(ssfire_init, arg)
+{
+ arg_free(arg);
+
+ if(id == EK_ID_NONE) {
+ id = ek_start(&p);
+ }
+}
+/*-----------------------------------------------------------------------------------*/
+static void
+fire_quit(void)
+{
+ *(char *)0xC051 = 0;
+
+ ek_exit();
+ id = EK_ID_NONE;
+ LOADER_UNLOAD();
+}
+/*-----------------------------------------------------------------------------------*/
+static void
+fire_init(void)
+{
+ *(char *)0xC056 = 0;
+ *(char *)0xC054 = 0;
+ *(char *)0xC052 = 0;
+ *(char *)0xC050 = 0;
+
+ for(y = 0; y < 24; ++y) {
+ gotoy(y);
+ for(x = 0; x < 40; ++x) {
+ (*(unsigned char **)0x28)[x] = 0x00;
+ }
+ }
+}
+/*-----------------------------------------------------------------------------------*/
+EK_EVENTHANDLER(ssfire_eventhandler, ev, data)
+{
+ EK_EVENTHANDLER_ARGS(ev, data);
+
+ if(ev == EK_EVENT_INIT) {
+ ctk_mode_set(CTK_MODE_SCREENSAVER);
+ ctk_mouse_hide();
+ fire_init();
+ } else if(ev == ctk_signal_screensaver_stop ||
+ ev == EK_EVENT_REQUEST_EXIT) {
+ fire_quit();
+ ctk_draw_init();
+ ctk_desktop_redraw(NULL);
+ }
+}
+/*-----------------------------------------------------------------------------------*/
+#pragma optimize(push, off)
+static void
+fire_burn(void)
+{
+ /* Calculate new flames. */
+ asm("ldy #$00");
+loop1:
+ asm("lda %v+7,y", flames);
+ asm("clc");
+ asm("adc %v+8,y", flames);
+ asm("adc %v+9,y", flames);
+ asm("adc %v+16,y", flames);
+ asm("lsr");
+ asm("lsr");
+ asm("sta %v,y", flames);
+ asm("iny");
+ asm("cpy #(8*15)");
+ asm("bne %g", loop1);
+
+ /* Fill last line with pseudo-random data. */
+ asm("ldy #$05");
+loop2:
+ asm("jsr %v", rand);
+ asm("and #$0F");
+ asm("sta %v+8*15+1,y", flames);
+ asm("dey");
+ asm("bpl %g", loop2);
+}
+#pragma optimize(pop)
+/*-----------------------------------------------------------------------------------*/
+EK_POLLHANDLER(ssfire_pollhandler)
+{
+ if(ctk_mode_get() == CTK_MODE_SCREENSAVER) {
+
+ fire_burn();
+
+ /* Display flames on screen. */
+ flameptr = flames;
+ for(y = 9; y < 24; ++y) {
+ gotoy(y);
+ for(x = 0; x < 8; ++x) {
+ (*(unsigned char **)0x28)[x ] =
+ (*(unsigned char **)0x28)[x+32] = flamecolors[flameptr[x]];
+ }
+ flameptr += 8;
+ }
+ }
+}
+/*-----------------------------------------------------------------------------------*/
+