From b51316eddeb231d7e7ff8d217e61e8d87942d51c Mon Sep 17 00:00:00 2001
From: Eldred Habert <eldredhabert0@gmail.com>
Date: Mon, 6 Jan 2020 11:27:48 +0100
Subject: [PATCH] Fix `MultiplyNumbers` macro

It used to shift the number left 11 times, not multiply it.
---
 gbasmdev.tex | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/gbasmdev.tex b/gbasmdev.tex
index f8f35bd..05322c9 100644
--- a/gbasmdev.tex
+++ b/gbasmdev.tex
@@ -376,10 +376,11 @@ \section{Loops}
   push bc ; lets us use B register
   ; without messing up existing data, 
   ; as it is restored before we return 
+  ld c, a
   
-  ld b, 11 ; the number of times we loop 
+  ld b, 10 ; the number of times we loop 
 .loop:
-  add a ; add A onto itself 
+  add c ; add the original value (in C) onto A
   dec b ; decrease loop counter 
   jr nz, .loop ; if didn't reach zero, go back
   ; If we got here, the loop is finished 
@@ -507,10 +508,10 @@ \section{Compile time operations}
 
 \begin{code}
 MultiplyNumbers: MACRO
-    ld a, \1
-    ld b, \2
+    ld bc, (\2) << 8 | (\1)
+    xor a
 .loop\@:
-    add a
+    add c
     dec b
     jr nz, .loop\@
 \end{code}