trying to figure out how to get 1s in .1s intervals

Makefile.avr

@@ -12,7 +12,7 @@ LDFLAGS += -mmcu=$(MCU)
 AVDFLAGS += -p $(MCU)
 AVDFLAGS += -c usbtiny
 
-FUSES += -U lfuse:w:0x7f:m
+FUSES += -U lfuse:w:0xff:m
 FUSES += -U hfuse:w:0xd9:m
 FUSES += -U efuse:w:0xff:m
 

avr.c

@@ -20,7 +20,7 @@ ISR(TIM0_OVF_vect)
 	
 	m += (256 * 64);
 	if (m >= JIFFY_uS) {
-		m %= JIFFY_uS;
+		m -= JIFFY_uS;
 		tick = true;
 		jiffies += 1;
 	}

avr.h

@@ -5,7 +5,6 @@
 #include <avr/io.h>
 #include <avr/interrupt.h>
 
-
 // Make sure JIFFY_uS is going to be an integer and not a float!
 #define JIFFIES_PER_SECOND 100
 #define JIFFY_uS (1000000 / JIFFIES_PER_SECOND)

main.c

@@ -241,17 +241,16 @@ void
 loop()
 {
 	uint32_t i;
-	
 
 	if (tick) {
 		tick = false;
 		
 		update_controller();
 
+		if (jiffies % 66 == 0) {
+			PORTB ^= 0xff;
+		}
 		if (jiffies % (JIFFIES_PER_SECOND / 10) == 0) {
-			if (jiffies % JIFFIES_PER_SECOND == 0) {
-				PORTB ^= 0xff;
-			}
 			switch (state) {
 			case SETUP:
 				break;