diff --git a/src/main.zig b/src/main.zig
index 7f4a908..533ad64 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -2,6 +2,7 @@ const std = @import("std");
 const silkdot = @import("silkdot");
 
 const Uxn = @import("uxn.zig");
+const UxnFmt = @import("uxn-instructions.zig");
 
 pub fn main() !void {
     var gpa = std.heap.GeneralPurposeAllocator(.{}){};
@@ -35,7 +36,7 @@ pub fn main() !void {
             //     },
             //     else => {},
             // };
-            std.debug.print("{any} {X}\n", .{ uxn.pc, uxn.mem.m[uxn.pc] });
+            std.debug.print("pc={X} code={X} op={s}\n", .{ uxn.pc, uxn.mem.m[uxn.pc], UxnFmt.fmtInstrs(uxn.mem.m[uxn.pc .. uxn.pc +% 1]) });
             if (uxn.eval()) running = false;
             // try term.draw();
         }
diff --git a/src/uxn-instructions.zig b/src/uxn-instructions.zig
new file mode 100644
index 0000000..78317b1
--- /dev/null
+++ b/src/uxn-instructions.zig
@@ -0,0 +1,61 @@
+const std = @import("std");
+
+pub fn formatInstruction(
+    bytes: []const u8,
+    comptime fmt: []const u8,
+    options: std.fmt.FormatOptions,
+    writer: anytype,
+) !void {
+    _ = fmt;
+    _ = options;
+    std.debug.assert(bytes.len == 1);
+    switch (bytes[0] & 0x1F) {
+        0x00 => switch (bytes[0]) {
+            0x00 => try writer.writeAll("BRK"),
+            0x20 => try writer.writeAll("JCI"),
+            0x40 => try writer.writeAll("JMI"),
+            0x60 => try writer.writeAll("JSI"),
+            0x80, 0xA0 => try writer.writeAll("LIT"),
+            else => unreachable,
+        },
+        0x01 => try writer.writeAll("INC"),
+        0x02 => try writer.writeAll("POP"),
+        0x03 => try writer.writeAll("NIP"),
+        0x04 => try writer.writeAll("SWP"),
+        0x05 => try writer.writeAll("ROT"),
+        0x06 => try writer.writeAll("DUP"),
+        0x07 => try writer.writeAll("OVR"),
+        0x08 => try writer.writeAll("EQU"),
+        0x09 => try writer.writeAll("NEQ"),
+        0x0A => try writer.writeAll("GTH"),
+        0x0B => try writer.writeAll("LTH"),
+        0x0C => try writer.writeAll("JMP"),
+        0x0D => try writer.writeAll("JCN"),
+        0x0E => try writer.writeAll("JSR"),
+        0x0F => try writer.writeAll("STH"),
+        0x10 => try writer.writeAll("LDZ"),
+        0x11 => try writer.writeAll("STZ"),
+        0x12 => try writer.writeAll("LDR"),
+        0x13 => try writer.writeAll("STR"),
+        0x14 => try writer.writeAll("LDA"),
+        0x15 => try writer.writeAll("STA"),
+        0x16 => try writer.writeAll("DEI"),
+        0x17 => try writer.writeAll("DEO"),
+        0x18 => try writer.writeAll("ADD"),
+        0x19 => try writer.writeAll("SUB"),
+        0x1A => try writer.writeAll("MUL"),
+        0x1B => try writer.writeAll("DIV"),
+        0x1C => try writer.writeAll("AND"),
+        0x1D => try writer.writeAll("ORA"),
+        0x1E => try writer.writeAll("EOR"),
+        0x1F => try writer.writeAll("SFT"),
+        else => unreachable,
+    }
+    if (bytes[0] & 0x20 == 0x20) try writer.writeByte('2');
+    if (bytes[0] & 0x40 == 0x40) try writer.writeByte('k');
+    if (bytes[0] & 0x80 == 0x80) try writer.writeByte('r');
+}
+
+pub fn fmtInstrs(bytes: []const u8) std.fmt.Formatter(formatInstruction) {
+    return .{ .data = bytes };
+}