1 files changed, 15 insertions, 0 deletions
diff --git a/isr.asm b/isr.asm
new file mode 100644
index 0000000..9ac6bb6
--- /dev/null
+++ b/isr.asm
@@ -0,0 +1,15 @@
+int21:
+	nop
+int22:
+	nop
+int20:
+	pusha
+	mov ax, cs
+	mov ds, ax
+	mov ax, 0b800h
+	mov es, ax
+
+	mov bp, 0000h
+	mov word [es:bp+79*2], 17h << 8 | 'B'
+	popa
+	iret