diff --git a/src/interpreter/mod.rs b/src/interpreter/mod.rs
index a926a29..c9cbf30 100644
--- a/src/interpreter/mod.rs
+++ b/src/interpreter/mod.rs
@@ -202,7 +202,7 @@ fn execute(instruction: u16, em: &mut Emulator) {
             let (x, sub_inst) = extract_0xii(instruction);
             #[allow(unreachable_code)]
             match sub_inst {
-                0x0F => { // set Vx = delay timer value
+                0x07 => { // set Vx = delay timer value
                     em.reg[x] = em.delay_t;
                 }
                 0x0A => { // wait for key and store it in Vx
@@ -234,12 +234,12 @@ fn execute(instruction: u16, em: &mut Emulator) {
                     em.memory[(em.i + 2) as usize] = n as u8;
                 }
                 0x55 => { // store registers V0 to Vx in memory I
-                    for i in 0..x as u16 {
+                    for i in 0..=x as u16 {
                         em.memory[(em.i + i) as usize] = em.reg[i as usize];
                     }
                 }
                 0x65 => { // load V0 to Vx from memory at I
-                    for i in 0..x as u16 {
+                    for i in 0..=x as u16 {
                         em.reg[i as usize] = em.memory[(em.i + i) as usize]
                     }
                 }
diff --git a/src/interpreter/test.rs b/src/interpreter/test.rs
index dde3dd5..83f1e26 100644
--- a/src/interpreter/test.rs
+++ b/src/interpreter/test.rs
@@ -3,6 +3,7 @@ use crate::interpreter::{Emulator, execute};
 #[test]
 fn instructions_0_1_2() {
     let mut em = Emulator::default();
+    //frame clearing is not implemented yet.
     em.pc = 10;
     execute(0x20FF, &mut em); // call 0FF
     assert_eq!(em.pc + 1, 0x0FF);
@@ -41,20 +42,138 @@ fn instructions_6_7() {
     assert_eq!(em.reg[0], 0xAC);
 }
 
+/// macros to simplify testing the 8xyz instructions
+macro_rules! test_reg_ops {
+    ($i:literal: $x:literal $y:literal => $z:literal for $em:ident) => {
+        $em.reg[0] = $x;
+        $em.reg[1] = $y;
+        crate::interpreter::execute($i, &mut $em);
+        assert_eq!($em.reg[0], $z);
+    }
+}
+/// macros to simplify testing the 8xyz instructions
+macro_rules! test_reg_ops_flag {
+    ($i:literal: $x:literal $y:literal => $z:literal + $f:literal for $em:ident) => {
+        $em.reg[0] = $x;
+        $em.reg[1] = $y;
+        crate::interpreter::execute($i, &mut $em);
+        assert_eq!($em.reg[0], $z);
+        assert_eq!($em.reg[0xF], $f);
+    }
+}
+
 #[test]
-fn instruction_fx33_conversion() {
+fn instructions_8xyz() {
     let mut em = Emulator::default();
+    em.reg[1] = 2;
+    // 0 store V1 in V0
+    execute(0x8010, &mut em);
+    assert_eq!(em.reg[0], 2);
+
+    // 1 OR V0 and V1, expected result in V2
+    test_reg_ops!(0x8011: 0b10011111 0b11010001 => 0b11011111 for em);
+
+    // 2 AND V0 and V1, expected result in V2
+    test_reg_ops!(0x8012: 0b11011111 0b10010001 => 0b10010001 for em);
+
+    // 3 XOR V0 and V1, expected result in V2
+    test_reg_ops!(0x8013: 0b11011111 0b10010001 => 0b01001110 for em);
+
+    // 4 ADD V0 to V1, overflow => flag
+    test_reg_ops_flag!(0x8014: 10 10 => 20 + 0 for em);
+    test_reg_ops_flag!(0x8014: 255 11 => 10 + 1 for em);
+
+    // 5 SUB V1 from V0, V0 > V1 => flag
+    test_reg_ops_flag!(0x8015: 20 10 => 10 + 1 for em);
+    test_reg_ops_flag!(0x8015: 0 1 => 255 + 0 for em);
+
+    // 6 SHR Shift V0 right by one bit, overflow => flag
+    test_reg_ops_flag!(0x8016: 0b10000000 0 => 0b01000000 + 0 for em);
+    test_reg_ops_flag!(0x8016: 0b00000001 0 => 0b00000000 + 1 for em);
+
+    // 7 Subtract V0 from V1, V1 > V0 => flag
+    test_reg_ops_flag!(0x8017: 10 20 => 10 + 1 for em);
+    test_reg_ops_flag!(0x8017: 1 0 => 255 + 0 for em);
+
+    // E SHL Shift V0 left by one bit, overflow => flag
+    test_reg_ops_flag!(0x801E: 0b00000001 0 => 0b00000010 + 0 for em);
+    test_reg_ops_flag!(0x801E: 0b10000000 0 => 0b00000000 + 1 for em);
+}
+
+#[test]
+fn instruction_9() {
+    let mut em = Emulator::default();
+    em.reg[0] = 10;
+    em.reg[1] = 11;
+    execute(0x9010, &mut em);
+    assert_eq!(em.pc, 1);
+    execute(0x9EE0, &mut em);
+    assert_eq!(em.pc, 1);
+}
+
+#[test]
+fn instruction_a_b_c() {
+    let mut em = Emulator::default();
+    execute(0xA123, &mut em);
+    assert_eq!(em.i, 0x123);
+    em.reg[0] = 100;
+    execute(0xB123, &mut em);
+    assert_eq!(em.pc, 100 + 0x123 - 1); // - 1 because the emulator does the next() at the end normally
+
+    execute(0xC000, &mut em);
+    assert_eq!(em.reg[0], 0); // is 0 because the kk value is AND with the random value
+    execute(0xC00F, &mut em);
+    assert!(em.reg[0] < 0x10);
+}
+
+#[test]
+fn instruction_f() {
+    let mut em = Emulator::default();
+
+    em.delay_t = 245;
+    execute(0xF007, &mut em);
+    assert_eq!(em.reg[0], 245);
+
+    execute(0xF115, &mut em); // set delay_t = V1
+    assert_eq!(em.delay_t, 0);
+
+    em.reg[0] = 13;
+    execute(0xF018, &mut em); // set sound_t = V0
+    assert_eq!(em.sound_t, 13);
+
+    em.reg[0] = 1;
+    em.i = 10;
+    execute(0xF01E, &mut em); // i = i + v0
+    assert_eq!(em.i, 11);
+
+    // Fx19 unimplemented
+
+
+    em.i = 0;
     em.reg[0] = 255;
     em.reg[1] = 99;
     em.reg[2] = 1;
-    let instruction1 = 0xF033;
-    let instruction2 = 0xF133;
-    let instruction3 = 0xF233;
-    execute(instruction1, &mut em);
+    execute(0xF033, &mut em);
     em.i = 3;
-    execute(instruction2, &mut em);
+    execute(0xF133, &mut em);
     em.i = 6;
-    execute(instruction3, &mut em);
+    execute(0xF233, &mut em);
 
     assert_eq!(&em.memory[0..9], &[2, 5, 5, 0, 9, 9, 0, 0, 1]);
-}
+
+    // store all registers from 0 including A in memory at i
+    for i in 0..=0xAu8 {
+        em.reg[i as usize] = i + 1;
+    }
+    em.i = 100;
+    execute(0xFA55, &mut em);
+    assert_eq!(&em.memory[100..=110], &[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]);
+
+    // load all registers from 0 including A from memory at i
+    for i in 0..=0xAu8 {
+        em.memory[i as usize] = i + 1;
+    }
+    em.i = 0;
+    execute(0xFA65, &mut em);
+    assert_eq!(&em.reg[0..=10], &[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]);
+}
\ No newline at end of file