diff --git a/.github/workflows/ti84-ref_app.yml b/.github/workflows/ti84-ref_app.yml
index 3b3e807..99220b5 100644
--- a/.github/workflows/ti84-ref_app.yml
+++ b/.github/workflows/ti84-ref_app.yml
@@ -32,3 +32,22 @@ jobs:
           make TYP_OS=UNIX all
           echo 'build-and-verify-refapp partial verify result'
           ls -la ../bin/refapp.8xp
+  gcc-build-native-macos:
+    runs-on: macos-latest
+    defaults:
+      run:
+        shell: bash
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: '0'
+      - name: get-sdcc-toolchain
+        run: |
+          brew install sdcc
+      - name: build-and-verify-refapp
+        run: |
+          cd build
+          sdcc -v
+          make TYP_OS=UNIX all
+          echo 'build-and-verify-refapp partial verify result'
+          ls -la ../bin/refapp.8xp
diff --git a/bin/refapp.asm b/bin/refapp.asm
index b08ad1a..c4bbfea 100644
--- a/bin/refapp.asm
+++ b/bin/refapp.asm
@@ -1,6 +1,6 @@
 ;--------------------------------------------------------
 ; File Created by SDCC : free open source ISO C Compiler 
-; Version 4.4.0 #14620 (MINGW32)
+; Version 4.4.0 #14620 (MINGW64)
 ;--------------------------------------------------------
 	.module app_main
 	.optsdcc -mz80
diff --git a/bin/refapp.lk b/bin/refapp.lk
index 1aa9dc6..1d6e648 100644
--- a/bin/refapp.lk
+++ b/bin/refapp.lk
@@ -2,7 +2,7 @@
 -i C:/Users/ckorm/Documents/Ks/uC_Software/Boards/ti84-ref_app/build/../bin/refapp.ihx
 -b _CODE = 0x9d9b
 -b _DATA = 0x0000
--k C:\Program Files (x86)\SDCC\bin\..\lib\z80
+-k C:\Program Files\SDCC\bin\..\lib\z80
 -l z80
 C:/Users/ckorm/Documents/Ks/uC_Software/Boards/ti84-ref_app/build/../bin/refapp.rel
 C:/Users/ckorm/Documents/Ks/uC_Software/Boards/ti84-ref_app/build/obj/app_hello.rel
diff --git a/bin/refapp.lst b/bin/refapp.lst
index 30c9890..2df55d2 100644
--- a/bin/refapp.lst
+++ b/bin/refapp.lst
@@ -1,6 +1,6 @@
                                       1 ;--------------------------------------------------------
                                       2 ; File Created by SDCC : free open source ISO C Compiler 
-                                      3 ; Version 4.4.0 #14620 (MINGW32)
+                                      3 ; Version 4.4.0 #14620 (MINGW64)
                                       4 ;--------------------------------------------------------
                                       5 	.module app_main
                                       6 	.optsdcc -mz80
diff --git a/build/Makefile b/build/Makefile
index 4fcae93..169f1a9 100644
--- a/build/Makefile
+++ b/build/Makefile
@@ -65,7 +65,7 @@ CP              := $(TOOL_PREFIX)cp$(EXEEXT)
 ECHO            := $(TOOL_PREFIX)echo$(EXEEXT)
 MKDIR           := $(TOOL_PREFIX)mkdir$(EXEEXT)
 MV              := $(TOOL_PREFIX)mv$(EXEEXT)
-OBJCOPY         := $(TOOL_PREFIX)objcopy$(EXEEXT)
+OBJCOPY         := sdobjcopy$(EXEEXT)
 PYTHON          := python$(EXEEXT)
 RM              := $(TOOL_PREFIX)rm$(EXEEXT)
 
diff --git a/build/tools/UnxUtils/usr/local/wbin/objcopy.exe b/build/tools/UnxUtils/usr/local/wbin/objcopy.exe
deleted file mode 100644
index 390e2ec..0000000
Binary files a/build/tools/UnxUtils/usr/local/wbin/objcopy.exe and /dev/null differ
diff --git a/readme.md b/readme.md
index f20567d..3caeaea 100644
--- a/readme.md
+++ b/readme.md
@@ -128,7 +128,8 @@ make TYP_OS=UNIX all
 Testing has been performed on the target system, which is a fully-functioning
 TI-84 Plus calculator purchased years ago from a commercial retailer.
 
-Continuous integration is performed on GHA using an ubuntu-latest runner.
+Continuous integration is performed on GHA using a ubuntu-latest
+and macos-latest runners.
 The [workflow run](./.github/workflows/ti84-ref_app.yml)
 builds the application and verifies the presence of `bin/refapp.8xp`.
 
@@ -166,5 +167,4 @@ from this.
 
   - The source code written for this repo (in the [`src`](./src)) directory is licensed under [_The_ _Unlicense_](./LICENSE).
   - `Win*`-ported `*nix` tools in [`wbin`](./build/tools/UnxUtils/usr/local/wbin) originate from [UnxTools](https://sourceforge.net/projects/unxutils) and include their own [distribution statements](./build/tools/UnxUtils).
-  - The `Win*`-ported `objcopy.exe` originates from Steven T. Lavavej's [`MinGW Distro`](https://nuwen.net/mingw.html).
   - The `Win*`-ported GNUmake is taken from [`ckormanyos/make-4.2.1-msvc-build`](https://github.com/ckormanyos/make-4.2.1-msvc-build).