diff --git a/extras/tests/simavr_based/Makefile b/extras/tests/simavr_based/Makefile
index b8502ba..150ca2b 100644
--- a/extras/tests/simavr_based/Makefile
+++ b/extras/tests/simavr_based/Makefile
@@ -46,39 +46,9 @@ simavr/simavr/run_avr: simavr/simavr/sim/run_avr.c
 	make -C simavr build-simavr
 
 simavr/simavr/sim/run_avr.c:
-	git clone https://github.com/gin66/simavr.git
-	# these versions work out of the box
-	#(cd simavr;git checkout	8d660ce)
-	#(cd simavr;git checkout	a56b550)
-	#(cd simavr;git checkout	c6d5375)
-	#(cd simavr;git checkout	9ed8eb6)
-	#(cd simavr;git checkout	b653a13)
-	#
-	# these versions work only with patch applied
-	#(cd simavr;git checkout	d2aaebd)
-	#(cd simavr;git checkout	ea4c450)
-	#(cd simavr;git checkout	d6ba83c)
-	#(cd simavr;git checkout	ce6738b)
-	#(cd simavr;git checkout	a5634af)
-	#(cd simavr;git checkout	13363d5)
-	#(cd simavr;git checkout	1379eed)
-	#
-	# these versions cannot be reverse patched
-	#(cd simavr;git checkout	c96ea61) # fails
-	#(cd simavr;git checkout	4d1750b) # fails
-	#(cd simavr;git checkout	adfce91) # fails
-	#
-	# test using:
-	#     make proper run_avr;make -C test_sd_01b_2560t3/
-	#
-	# patch derived by:
-	#     git diff b653a13..d2aaebd >../../simavr.patch
-	#
-	# select current HEAD as of now
-	(cd simavr;git checkout	7003af)
-	# apply patch, which is now minimal:
-#	(cd simavr;patch -p1 -t <../simavr.patch)
-	(cd simavr;patch -p1 -t <../simavr.patch2)
+	# git clone https://github.com/gin66/simavr.git
+	git clone https://github.com/buserror/simavr.git
+	(cd simavr;git checkout	132cc67)
 
 proper: clean
 	rm -f run_avr
diff --git a/extras/tests/simavr_based/simavr.patch b/extras/tests/simavr_based/simavr.patch
deleted file mode 100644
index 0b042fa..0000000
--- a/extras/tests/simavr_based/simavr.patch
+++ /dev/null
@@ -1,16 +0,0 @@
-diff --git a/simavr/sim/avr_ioport.c b/simavr/sim/avr_ioport.c
-index 91cf106..3d489d5 100644
---- a/simavr/sim/avr_ioport.c
-+++ b/simavr/sim/avr_ioport.c
-@@ -158,6 +158,11 @@ avr_ioport_irq_notify(
- 	value &= 0xff;
- 	uint8_t mask = 1 << irq->irq;
- 	uint8_t ddr = avr->data[p->r_ddr];
-+	// Set the real PIN bit. Ignore DDR as it's masked when read.
-+
-+	avr->data[p->r_pin] &= ~mask;
-+	if (value)
-+		avr->data[p->r_pin] |= mask;
- 
- 	if (output) {
- 		if ((mask & ddr) == 0)
diff --git a/extras/tests/simavr_based/simavr.patch2 b/extras/tests/simavr_based/simavr.patch2
deleted file mode 100644
index 216ecd8..0000000
--- a/extras/tests/simavr_based/simavr.patch2
+++ /dev/null
@@ -1,52 +0,0 @@
-diff --git a/simavr/sim/avr_ioport.c b/simavr/sim/avr_ioport.c
-index 91cf106..b1dba73 100644
---- a/simavr/sim/avr_ioport.c
-+++ b/simavr/sim/avr_ioport.c
-@@ -155,27 +155,34 @@ avr_ioport_irq_notify(
- 	avr_t * avr = p->io.avr;
- 
- 	int output = value & AVR_IOPORT_OUTPUT;
--	value &= 0xff;
- 	uint8_t mask = 1 << irq->irq;
- 	uint8_t ddr = avr->data[p->r_ddr];
-+	uint8_t new_pin;
- 
-+	value &= 0xff;
-+	new_pin = (avr->data[p->r_pin] & ~mask) | (value ? mask : 0);
- 	if (output) {
--		if ((mask & ddr) == 0)
--			return;	   // TODO: stop further processing of IRQ.
--
--		// If the IRQ was marked as Output, also do the IO write.
-+		uint8_t new_out;
-+
-+		new_out = (avr->data[p->r_port] & ~mask) | (value ? mask : 0);
-+		if (mask & ddr) {
-+			// If the IRQ was marked as Output, do the IO write.
-+
-+			avr_ioport_write(avr, p->r_port, new_out, p);
-+			avr_core_watch_write(avr, p->r_pin, new_pin);
-+		} else {
-+			/* Set the PORT register so the output will be visible
-+			 * when the corresponding DDR bit is set.
-+			 * Real hardware does not do this.
-+			 */
- 
--		avr_ioport_write(avr,
--				 p->r_port,
--				 (avr->data[p->r_port] & ~mask) |
--				     (value ? mask : 0),
--				 p);
-+			avr->data[p->r_port] = new_out;
-+			return;	   // TODO: stop further processing of IRQ.
-+		}
- 	} else {
- 		// Set the real PIN bit. Ignore DDR as it's masked when read.
- 
--		avr_core_watch_write(avr, p->r_pin,
--							 (avr->data[p->r_pin] & ~mask) |
--								(value ? mask : 0));
-+		avr_core_watch_write(avr, p->r_pin, new_pin);
- 
- 		/* BUG: If DDR bit is set here, there should be no
- 		 * interrupt.  But a spurious IRQ call by the user