diff --git a/defines_osi.s b/defines_osi.s
index 0b6f3e7..b2efaf6 100644
--- a/defines_osi.s
+++ b/defines_osi.s
@@ -1,4 +1,6 @@
 ; configuration
+CONFIG_10A := 1
+
 CONFIG_DATAFLAG := 1
 CONFIG_NULL := 1
 CONFIG_PRINT_CR := 1 ; print CR when line end reached
diff --git a/eval.s b/eval.s
index e71d757..c251e6c 100644
--- a/eval.s
+++ b/eval.s
@@ -499,6 +499,7 @@ L2DC2:
 .endif
 .ifdef CONFIG_CBM1_PATCHES
         jmp     PATCH3
+        .byte   $19
 .endif
 .ifdef CBM2
         bit     $62
@@ -509,9 +510,6 @@ L2DC2:
 .ifndef CONFIG_CBM_ALL
         jmp     LOAD_FAC_FROM_YA
 .endif
-.ifdef CBM1
-        .byte   $19
-.endif
 .ifdef CONFIG_CBM_ALL
 LCE69:
         cpy     #$49
diff --git a/float.s b/float.s
index 4400a97..179d4b1 100644
--- a/float.s
+++ b/float.s
@@ -1331,11 +1331,11 @@ GETEXP:
         lda     EXPON
         cmp     #MAX_EXPON
         bcc     L3C2C
-.ifndef CBM1
+.ifdef CONFIG_10A
         lda     #$64
 .endif
         bit     EXPSGN
-.ifndef CBM1
+.ifdef CONFIG_10A
         bmi     L3C3A
 .else
         bmi     LDC70
diff --git a/program.s b/program.s
index df14181..b378c9e 100644
--- a/program.s
+++ b/program.s
@@ -1,3 +1,9 @@
+; error
+; line input, line editing
+; tokenize
+; detokenize
+; BASIC program memory management
+
 ; MICROTAN has some nonstandard extension to LIST here
 
 .segment "CODE"