diff --git a/Makefile b/Makefile
index 934e38a..c348058 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 # Makefile for 'tester.hex'
 
-AS=z80asm
-APPMAKE=appmake
+AS=z88dk-z80asm
+APPMAKE=z88dk-appmake
 PPZSUM=ppzsum
 
 all: tester.hex
diff --git a/tester.asm b/tester.asm
index 69b6954..e5388c0 100644
--- a/tester.asm
+++ b/tester.asm
@@ -93,7 +93,7 @@ RST38:      reti                ; Interrupt mode 1 address. Ignore and return
 
 mcinit:     ld a,$03            ; Reset 6850 ACIA
             out (ACIAS),a
-            ld a,$96            ; Initialise ACIA to divide-by-64
+            ld a,$94            ; Initialise ACIA to divide-by-1
             out (ACIAS),a
 
             ; TODO: initialise all the other RC2014 I/O devices
diff --git a/tester.hex b/tester.hex
index 94c2e02..2aa0ed2 100644
--- a/tester.hex
+++ b/tester.hex
@@ -1,7 +1,7 @@
 :10000000F3ED5631FFFF1832E90000000000000058
 :10001000E900000000000000E9000000000000000E
 :10002000E900000000000000E900000000000000FE
-:10003000E900000000000000ED4D3E03D3803E9635
+:10003000E900000000000000ED4D3E03D3803E9437
 :10004000D380218500FD214C00C356083E3EFD2192
 :100050005500C33408215B00C37408FD216200C34E
 :100060003408E65FFE41FA8200FE5BF28200D64170