From 1d2d95072919cb1450936c659f7593ebc21c899c Mon Sep 17 00:00:00 2001
From: Michel Heily <michelheily@gmail.com>
Date: Sat, 24 Aug 2019 00:33:01 +0300
Subject: [PATCH] Fix IoRegs::write_8

Former-commit-id: 9877e7f42fefafb71dd319287e01d55926d4d12c
---
 src/core/gpu/{blend.rs => sfx.rs} |  0
 src/core/ioregs.rs                | 14 ++++++++++++--
 2 files changed, 12 insertions(+), 2 deletions(-)
 rename src/core/gpu/{blend.rs => sfx.rs} (100%)

diff --git a/src/core/gpu/blend.rs b/src/core/gpu/sfx.rs
similarity index 100%
rename from src/core/gpu/blend.rs
rename to src/core/gpu/sfx.rs
diff --git a/src/core/ioregs.rs b/src/core/ioregs.rs
index 193fbbc..abf1edc 100644
--- a/src/core/ioregs.rs
+++ b/src/core/ioregs.rs
@@ -286,8 +286,18 @@ impl Bus for IoRegs {
     }
 
     fn write_8(&mut self, addr: Addr, value: u8) {
-        let t = self.read_16(addr);
-        self.write_16(addr, (t & 0xff) | ((value as u16) << 8));
+        if addr & 1 != 0 {
+            let addr = addr & !1;
+            let t = self.read_16(addr);
+            let upper = (value as u16);
+            let lower = t & 0xff;
+            self.write_16(addr, (upper << 8) | lower);
+        } else {
+            let t = self.read_16(addr);
+            let upper = t << 8;
+            let lower = (value as u16);
+            self.write_16(addr, (upper << 8) | lower);
+        }
     }
 }