diff --git a/Makefile b/Makefile
index 68fb208..e21197f 100644
--- a/Makefile
+++ b/Makefile
@@ -69,7 +69,7 @@ dev: dev-image	## Launch a dev container
 
 
 .PHONY: binaries
-binaries:		## Build all binaries
+binaries:		## Build all small binaries
 	docker build --build-arg TARGET=readfloppy.bin -o . --target=export .
 	docker build --build-arg TARGET=writefloppy.bin -o . --target=export .
 	docker build --build-arg TARGET=crc16.bin -o . --target=export .
@@ -77,11 +77,9 @@ binaries:		## Build all binaries
 	docker build --build-arg TARGET=hello.bin -o . --target=export .
 	docker build --build-arg TARGET=copy.bin -o . --target=export .
 	docker build --build-arg TARGET=call.bin -o . --target=export .
-	docker build --build-arg TARGET=debug.bin -o . --target=export .
-	docker build --build-arg TARGET=dosdbt.bin -o . --target=export .
 	docker build --build-arg TARGET=format.bin -o . --target=export .
-	docker build --build-arg TARGET=polmon.com -o . --target=export .
-	docker build --build-arg TARGET=fat12boot.bin -o . --target=export .
+	docker build --build-arg TARGET=readio.bin -o . --target=export .
+	docker build --build-arg TARGET=writeio.bin -o . --target=export .
 
 .PHONY: floppy
 floppy:			## Make a bootable floppy image
diff --git a/readio.asm b/readio.asm
new file mode 100644
index 0000000..618a1e5
--- /dev/null
+++ b/readio.asm
@@ -0,0 +1,10 @@
+BITS 16
+CPU 8086
+
+_start:
+    mov bp, sp
+    mov si, [bp+4]
+    mov dx, [si]
+    xor ax, ax
+    in al, dx
+    retf 2
diff --git a/writeio.asm b/writeio.asm
new file mode 100644
index 0000000..799eec5
--- /dev/null
+++ b/writeio.asm
@@ -0,0 +1,12 @@
+BITS 16
+CPU 8086
+
+_start:
+    mov bp, sp
+    mov si, [bp+6]
+    mov dx, [si]
+    xor ax, ax
+    mov si, [bp+4]
+    mov al, [si]
+    out dx, al
+    retf 4