@@ -122,7 +122,7 @@ static const char *errors[] = {"underflow", "overflow", "division by zero"};

 int

 haltuxn(Uxn *u, Uint8 error, char *name, int id)

 {

-	printf("Halted: %s %s#%04x, at 0x%04x\n", name, errors[error - 1], id, u->ram.ptr);

+	fprintf(stderr, "Halted: %s %s#%04x, at 0x%04x\n", name, errors[error - 1], id, u->ram.ptr);

 	u->ram.ptr = 0;

 	return 0;

 }

@@ -180,11 +180,11 @@ loaduxn(Uxn *u, char *filepath)

 {

 	FILE *f;

 	if(!(f = fopen(filepath, "rb"))) {

-		printf("Halted: Missing input rom.\n");

+		fprintf(stderr, "Halted: Missing input rom.\n");

 		return 0;

 	}

 	fread(u->ram.dat + PAGE_PROGRAM, sizeof(u->ram.dat) - PAGE_PROGRAM, 1, f);

-	printf("Uxn loaded[%s].\n", filepath);

+	fprintf(stderr, "Uxn loaded[%s].\n", filepath);

 	return 1;

 }

@@ -196,6 +196,6 @@ portuxn(Uxn *u, Uint8 id, char *name, void (*talkfn)(Device *d, Uint8 b0, Uint8

 	d->u = u;

 	d->mem = u->ram.dat;

 	d->talk = talkfn;

-	printf("Device added #%02x: %s, at 0x%04x \n", id, name, d->addr);

+	fprintf(stderr, "Device added #%02x: %s, at 0x%04x \n", id, name, d->addr);

 	return d;

 }

@@ -38,7 +38,7 @@ clamp(int val, int min, int max)

 int

 error(char *msg, const char *err)

 {

-	printf("Error %s: %s\n", msg, err);

+	fprintf(stderr, "Error %s: %s\n", msg, err);

 	return 0;

 }

@@ -93,7 +93,7 @@ screencapture(void)

 	SDL_RenderReadPixels(gRenderer, NULL, format, surface->pixels, surface->pitch);

 	SDL_SaveBMP(surface, "screenshot.bmp");

 	SDL_FreeSurface(surface);

-	printf("Saved screenshot.bmp\n");

+	fprintf(stderr, "Saved screenshot.bmp\n");

 }

 void

@@ -269,10 +269,10 @@ file_talk(Device *d, Uint8 b0, Uint8 w)

 		Uint16 addr = mempeek16(d->dat, b0 - 1);

 		FILE *f = fopen(name, read ? "r" : (offset ? "a" : "w"));

 		if(f) {

-			printf("%s %04x %s %s: ", read ? "Loading" : "Saving", addr, read ? "from" : "to", name);

+			fprintf(stderr, "%s %04x %s %s: ", read ? "Loading" : "Saving", addr, read ? "from" : "to", name);

 			if(fseek(f, offset, SEEK_SET) != -1)

 				result = read ? fread(&d->mem[addr], 1, length, f) : fwrite(&d->mem[addr], 1, length, f);

-			printf("%04x bytes\n", result);

+			fprintf(stderr, "%04x bytes\n", result);

 			fclose(f);

 		}

 		mempoke16(d->dat, 0x2, result);