From d3d7dd43e8947fa046dec7480f776b5741a37f0a Mon Sep 17 00:00:00 2001
From: mothcompute <94941435+mothcompute@users.noreply.github.com>
Date: Thu, 9 Jun 2022 03:31:57 -0700
Subject: [PATCH] make bootable

---
 boot.s | 41 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)
 create mode 100644 boot.s

diff --git a/boot.s b/boot.s
new file mode 100644
index 0000000..7b02c2a
--- /dev/null
+++ b/boot.s
@@ -0,0 +1,41 @@
+; assemble this and concatenate sp2.com with it to make it bootable!
+
+[org 0x7C00]
+[bits 16]
+
+NUMSEG equ (1993/512)+1 ; filesize is 1993 bytes
+
+mov ax, 0x100
+mov ss, ax
+mov ds, ax
+mov es, ax
+mov gs, ax
+mov fs, ax
+mov bp, 0xF000
+mov sp, bp
+
+mov bx, 0x100
+mov al, NUMSEG
+inc ah
+mov cl, ah
+xor ch, ch
+xor dh, dh
+int 13h
+
+xor cx, cx
+mov ds, cx
+mov word [ds:0x21*4], int21
+mov word [ds:0x21*4+2], 0
+
+inc ch
+mov ds, cx
+push 0x100
+push 0x100
+retf
+
+int21:
+hlt
+
+times 510 - ($-$$) db 0
+
+dw 0xAA55