diff --git a/hyphae/src/vm.rs b/hyphae/src/vm.rs
index 9372d16..77b85ad 100644
--- a/hyphae/src/vm.rs
+++ b/hyphae/src/vm.rs
@@ -16,7 +16,7 @@
  */
 
 
-use organelle::{Fraction, Number, Numeric};
+use organelle::{Float, Fraction, Number, Numeric};
 
 use crate::hmap::QuickMap;
 use crate::stackstack::StackStack;
@@ -391,6 +391,28 @@ impl VM {
                 }
             }),
 
+            i::NTOBV => access!(&instr.1[0], {
+                if let Datum::Number(snum) = **access!(&instr.1[0]) {
+                    let n = snum.make_inexact();
+                    if !snum.is_exact() || n.0.fract() != 0.0 ||
+                        n.0 > u8::MAX.into() || n.0 < 0.0 {
+                            e!("input to NTOBV cannot cleanly convert");
+                        }
+                    Datum::ByteVector(n.0.to_ne_bytes().to_vec()).into()
+                } else {
+                    e!("illegal argument to NTOBV instruction");
+                }
+            }),
+
+            i::BVTON => access!(&instr.1[0], {
+                if let Datum::ByteVector(sbv) = &**access!(&instr.1[0]) {
+                    let sf64 = f64::from_ne_bytes(sbv.clone().try_into().unwrap());
+                    Datum::Number(Number::Flt(Float(sf64))).into()
+                } else {
+                    e!("illegal argument to BVTON instruction");
+                }
+            }),
+
             i::NTOC => access!(&instr.1[0], {
                 if let Datum::Number(snum) = **access!(&instr.1[0]) {
                     let n = snum.make_inexact();
@@ -1090,16 +1112,16 @@ mod tests {
     #[test]
     fn isa_conversions() {
         let mut vm = VM::from(Program(vec![], vec![
+
             // load from stack into expr
             Instruction(i::DUPL,  vec![Operand(Address::Stack, 0),
                                        Operand(Address::Expr,  0)]),
 
-            // create a strunct and push to stack
+            // create a struct and push to stack
             Instruction(i::CTOS,  vec![Operand(Address::Expr, 0)]),
             Instruction(i::PUSH,  vec![Operand(Address::Expr, 0)]),
 
             // reset expr to original char
-
             Instruction(i::DUPL,  vec![Operand(Address::Stack, 1),
                                        Operand(Address::Expr,  0)]),
 
@@ -1115,9 +1137,18 @@ mod tests {
             Instruction(i::NTOE,  vec![Operand(Address::Expr, 0)]),
             Instruction(i::PUSH,  vec![Operand(Address::Expr, 0)]),
 
+            // convert to ByteVector and push to stack
+            Instruction(i::NTOBV, vec![Operand(Address::Expr, 0)]),
+            Instruction(i::PUSH,  vec![Operand(Address::Expr, 0)]),
+
+            // convert back to inexact and push to stack
+            Instruction(i::BVTON, vec![Operand(Address::Expr, 0)]),
+            Instruction(i::PUSH,  vec![Operand(Address::Expr, 0)]),
+
             // create a char and push to stack
             Instruction(i::NTOC,  vec![Operand(Address::Expr, 0)]),
             Instruction(i::PUSH,  vec![Operand(Address::Expr, 0)]),
+
         ])).with_stack({
             let mut i = StackStack::new();
             i.push_current_stack(Datum::Char(b'a').into());
@@ -1127,12 +1158,14 @@ mod tests {
         let case = TestResult{
             expr: None,
             stack: vec![
-                (0, Datum::Char(b'a').into()),
-                (1, Datum::Number(Number::Fra(Fraction(97, 1))).into()),
-                (2, Datum::Number(Number::Flt(Float(97.0))).into()),
-                (3, Datum::Number(Number::Fra(Fraction(97, 1))).into()),
-                (4, Datum::String(vec![b'a']).into()),
-                (5, Datum::Char(b'a').into()),
+                (0, Datum::Char(b'a').into()), // NTOC
+                (1, Datum::Number(Number::Flt(Float(97.0))).into()), // BVTON
+                (2, Datum::ByteVector(vec![0, 0, 0, 0, 0, 64, 88, 64]).into()), // NTOBV
+                (3, Datum::Number(Number::Fra(Fraction(97, 1))).into()), // NTOE
+                (4, Datum::Number(Number::Flt(Float(97.0))).into()), // NTOI
+                (5, Datum::Number(Number::Fra(Fraction(97, 1))).into()), // CTON
+                (6, Datum::String(vec![b'a']).into()), // CTOS
+                (7, Datum::Char(b'a').into()), // DUPL
             ],
             syms: vec![],
             errr: None,
diff --git a/hyphae/vm.toml b/hyphae/vm.toml
index b445a25..9b2d5d5 100644
--- a/hyphae/vm.toml
+++ b/hyphae/vm.toml
@@ -641,6 +641,34 @@ character byte.
 Requires mutable access to input address.
 """
 
+[[instructions]]
+name = "ntobv"
+args = ["src"]
+output = ""
+description = """
+The ntobv instruction accepts a single number input. This operand is overwritten
+by a new number datum that represents the inexact form of the source number.
+
+The inexact form is a normalization of fraction or scientific notation datum to
+float datum casted to ByteVector datum.
+
+Requires mutable access to input address.
+"""
+
+[[instructions]]
+name = "bvton"
+args = ["src"]
+output = ""
+description = """
+The bvton instruction accepts a byte vector input. This operand is overwritten
+by a new number datum that represents the inexact form of the source byte vector.
+
+The normalized fraction or scientific notation data represented in a
+ByteVector datum is casted to an inexact floating point number.
+
+Requires mutable access to input address.
+"""
+
 [[instructions]]
 name = "ntoc"
 args = ["src"]