diff --git a/2022/RESULTS.txt b/2022/RESULTS.txt
index 41857ac..c98712a 100644
--- a/2022/RESULTS.txt
+++ b/2022/RESULTS.txt
@@ -203,15 +203,29 @@ aoc-c: res=2376
 +++++++++++++++++ part 1
 aoc.bash: res=13220
 	time: 0:00.00 real, 0.00 user, 0.00 sys
-	context-switch:	1+1, page-faults: 0+261
+	context-switch:	0+1, page-faults: 0+260
+
+aoc-c: res=13220
+	time: 0:00.00 real, 0.00 user, 0.00 sys
+	context-switch:	0+1, page-faults: 0+88
 
 +++++++++++++++++ part 2
 aoc.bash: res=
-###..#..#..##..#..#.#..#.###..####.#..#.
+###..#..#..##..#..#.#..#.###..####.#..##
 #..#.#..#.#..#.#.#..#..#.#..#.#....#.#..
-#..#.#..#.#..#.##...####.###..###..##...
-###..#..#.####.#.#..#..#.#..#.#....#.#..
+#..#.#..#.#..#.##...####.###..###..##..#
+###..#..#.####.#.#..#..#.#..#.#....#.#.#
 #.#..#..#.#..#.#.#..#..#.#..#.#....#.#..
 #..#..##..#..#.#..#.#..#.###..####.#..#.
 	time: 0:00.01 real, 0.00 user, 0.00 sys
-	context-switch:	0+1, page-faults: 0+263
+	context-switch:	3+1, page-faults: 0+262
+
+###..#..#..##..#..#.#..#.###..####.#..##
+#..#.#..#.#..#.#.#..#..#.#..#.#....#.#..
+#..#.#..#.#..#.##...####.###..###..##..#
+###..#..#.####.#.#..#..#.#..#.#....#.#.#
+#.#..#..#.#..#.#.#..#..#.#..#.#....#.#..
+#..#..##..#..#.#..#.#..#.###..####.#..#.
+aoc-c: res=0
+	time: 0:00.00 real, 0.00 user, 0.00 sys
+	context-switch:	0+1, page-faults: 0+88
diff --git a/2022/day10/aoc-c.c b/2022/day10/aoc-c.c
new file mode 100644
index 0000000..04ba084
--- /dev/null
+++ b/2022/day10/aoc-c.c
@@ -0,0 +1,167 @@
+/* aoc-c.c: Advent of Code 2022, day 10
+ *
+ * Copyright (C) 2022 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "br.h"
+#include "debug.h"
+
+#include "aoc.h"
+
+#define MAXARGS 1                                 /* max arguments to opcode */
+
+typedef enum opcode {                             /* available opcodes */
+    ERR  = -1,
+    NOOP =  0,
+    ADDX
+} opcode_t;
+
+typedef struct hw {                               /* hardware */
+    int tick;                                     /* clock */
+    int regx;                                     /* x register */
+    int signal;                                   /* signal strength */
+    int alrm;                                     /* next tick signal */
+    int rearm;                                    /* rearm signal value */
+    void (* tickfct)(struct hw *hw);              /* tick function */
+    void (* alrmfct)(struct hw *hw);              /* signal function */
+    int part;                                     /* puzzle part */
+} hw_t;
+
+typedef struct op {                               /* operators indormation */
+    char *mnemo;
+    opcode_t opcode;
+    int ticks;
+    void (* fct)(hw_t *hw, int *);
+    int nargs;
+} op_t;
+
+static inline void alarm1(hw_t *hw)
+{
+    hw->signal += hw->tick * hw->regx;
+    hw->alrm = hw->rearm;
+}
+
+static inline void alarm2(hw_t *hw)
+{
+    putchar('\n');                                /* '.' fixes last column garbage */
+    hw->alrm = hw->rearm;
+}
+
+static inline void tick1(__unused hw_t *hw)
+{
+}
+
+static inline void tick2(hw_t *hw)
+{
+    int pos = abs(hw->tick % 40 - hw->regx - 1);
+    putchar(pos < 2? '#': '.');
+}
+
+static void bootstrap(hw_t *hw, int part)
+{
+    hw->tick = 0;
+    hw->regx = 1;
+    hw->signal = 0;
+    hw->alrm = part == 1? 20: 40;
+    hw->rearm = 40;
+    hw->alrmfct = part == 1?  alarm1: alarm2;
+    hw->tickfct = part == 1?  tick1: tick2;
+    hw->part = part;
+}
+
+static inline void tick(hw_t *hw)
+{
+    hw->tick++;
+    hw->alrm--;
+    hw->tickfct(hw);
+    if (!hw->alrm)
+        hw->alrmfct(hw);
+}
+
+static inline void ticks(hw_t *hw, int ticks)
+{
+    for (int i = 0; i < ticks; ++i)
+        tick(hw);
+}
+
+static void do_noop(__unused hw_t *hw, __unused int *args)
+{
+}
+
+static void do_addx(hw_t *hw, int *args)
+{
+    hw->regx += *args;
+}
+
+static op_t opcodes[] = {
+    { "noop", NOOP, 1, do_noop, 0 },
+    { "addx", ADDX, 2, do_addx, 1 }
+};
+
+#define NOPS ARRAY_SIZE(opcodes)
+
+static op_t *getop(const char *mnemo)
+{
+    for (ulong i = 0; i < NOPS; ++i)
+        if (!strcmp(mnemo, opcodes[i].mnemo))
+            return opcodes + i;
+    return NULL;
+}
+
+static int part1(hw_t *hw)
+{
+    return hw->signal;
+}
+
+static int part2(hw_t *hw)
+{
+    return hw->signal;
+}
+
+static int parse(hw_t *hw)
+{
+    size_t alloc = 0;
+    char *buf = NULL;
+    ssize_t buflen;
+    char *token;
+    op_t *op;
+    int args[MAXARGS];
+
+    while ((buflen = getline(&buf, &alloc, stdin)) > 0) {
+        buf[--buflen] = 0;
+        if ((token = strtok(buf, " "))) {
+            if ((op = getop(token))) {
+                ticks(hw, op->ticks);
+                for (int i = 0; i < op->nargs; ++i)
+                    args[i] = atoi(strtok(NULL, " "));
+                op->fct(hw, args);
+            } else {
+                fprintf(stderr, "Fatal: opcode [%s] not found\n", token);
+                exit(1);
+            }
+        }
+    }
+    return 1;
+}
+
+int main(int ac, char **av)
+{
+    int part = parseargs(ac, av);
+    hw_t hw;
+
+    bootstrap(&hw, part);
+    parse(&hw);
+    printf("%s: res=%d\n", *av, part == 1? part1(&hw): part2(&hw));
+    exit(0);
+}
diff --git a/2022/day10/aoc.bash b/2022/day10/aoc.bash
index 22c49fb..651d710 100755
--- a/2022/day10/aoc.bash
+++ b/2022/day10/aoc.bash
@@ -18,11 +18,10 @@ declare -i cycle=0 regx=1
 draw() {
     local -i pos
 
-    if (( cycle % 40 )); then
-        (( pos = cycle % 40 - regx - 1, pos = pos < 0? -pos: pos ))
-        (( pos < 2 )) && res+="#" || res+="."
-    else
-        res+=.$'\n'
+    (( pos = cycle % 40 - regx - 1, pos = pos < 0? -pos: pos ))
+    (( pos < 2 )) && res+="#" || res+="."
+    if ! (( cycle % 40 )); then
+        res+=$'\n'
     fi
 }