diff --git a/client/clients/rrnetboot.s b/client/clients/rrnetboot.s
index b8e61fe..5a342db 100644
--- a/client/clients/rrnetboot.s
+++ b/client/clients/rrnetboot.s
@@ -71,7 +71,7 @@ nb65_param_buffer: .res $20
 .word init  ;cold start vector
 .word $FE47  ;warm start vector
 .byte $C3,$C2,$CD,$38,$30 ; "CBM80"
-.byte "NB65"  ;netboot 65 signature
+.byte $4E,$42,$36,$35  ; "NB65"  - API signature
 jmp nb65_dispatcher    ; NB65_DISPATCH_VECTOR   : entry point for NB65 functions
 jmp ip65_process          ;NB65_PERIODIC_PROCESSING_VECTOR : routine to be periodically called to check for arrival of ethernet packects
 jmp timer_vbl_handler     ;NB65_VBL_VECTOR : routine to be called during each vertical blank interrupt
@@ -104,7 +104,16 @@ init:
   ldax #__DATA_SIZE__
   jsr copymem
 
+;copy the RAM stub to RAM
+  ldax #nb65_ram_stub
+  stax copy_src
+  ldax #NB65_RAM_STUB_SIGNATURE
+  stax copy_dest
+  ldax #nb65_ram_stub_length
+  jsr copymem
 
+  
+  
   ldax  #startup_msg 
   jsr print
 
@@ -340,3 +349,11 @@ no_files_on_server:
 
 press_a_key_to_continue:
   .byte "PRESS A KEY TO CONTINUE",13,0
+
+nb65_ram_stub: ; this gets copied to $C000 so programs can bank in the cartridge
+.byte $4E,$42,$36,$35  ; "NB65"  - API signature
+  lda #$01    
+  sta $de00   ;turns on RR cartridge (since it will have been banked out when exiting to BASIC)
+  rts
+nb65_ram_stub_end:
+nb65_ram_stub_length=nb65_ram_stub_end-nb65_ram_stub
\ No newline at end of file
diff --git a/client/inc/nb65_constants.i b/client/inc/nb65_constants.i
index a76ef32..5b51f46 100644
--- a/client/inc/nb65_constants.i
+++ b/client/inc/nb65_constants.i
@@ -2,10 +2,13 @@
 
 NB65_API_VERSION=$0001
 
+
+NB65_CART_SIGNATURE             = $8009
 NB65_DISPATCH_VECTOR            = $800d 
 NB65_PERIODIC_PROCESSING_VECTOR = $8010
 NB65_VBL_VECTOR                 = $8013
-
+NB65_RAM_STUB_SIGNATURE         = $C000
+NB65_RAM_STUB_ACTIVATE          = $C004
 
 ;function numbers
 ;to make a function call:
diff --git a/client/test/test_cart_api.s b/client/test/test_cart_api.s
index 57217d8..8a629bd 100644
--- a/client/test/test_cart_api.s
+++ b/client/test/test_cart_api.s
@@ -63,16 +63,41 @@ basicstub:
 @nextline:
 	.word 0
 
+
+look_for_signature: ;look for NB65 signature at location pointed at by AX
+  stax temp_ptr
+  ldy #3
+@check_one_byte:
+  lda (temp_ptr),y
+  cmp nb65_signature,y
+  bne @bad_match  
+  dey 
+  bpl@check_one_byte  
+  clc
+  rts
+@bad_match:
+  sec
+  rts
+  
 init:
   
-  lda #$01    
-  sta $de00   ;turns on RR cartridge (since it will have been banked out when exiting to BASIC)
 
-  ldy #NB65_GET_DRIVER_NAME
-  jsr NB65_DISPATCH_VECTOR 
+  ldax #NB65_CART_SIGNATURE  ;where signature should be in cartridge
+  jsr  look_for_signature
+  bcc @found_nb65_signature
+
+  ldax #NB65_RAM_STUB_SIGNATURE  ;where signature should be in RAM
+  jsr  look_for_signature
+  bcc :+
+  jmp nb65_signature_not_found
+:  
+  jsr NB65_RAM_STUB_ACTIVATE     ;we need to turn on NB65 cartridge
   
-  ldy #NB65_PRINT_ASCIIZ
-  jsr NB65_DISPATCH_VECTOR
+@found_nb65_signature:
+  call #NB65_GET_DRIVER_NAME
+  
+  
+  call #NB65_PRINT_ASCIIZ
 
   print #initializing
 
@@ -216,6 +241,7 @@ udp_callback:
   
 bad_boot:
   print  #press_a_key_to_continue
+restart:    
   jsr get_key
   jmp $fce2   ;do a cold start
 
@@ -227,6 +253,17 @@ print_errorcode:
   print_cr
   rts
 
+nb65_signature_not_found:
+
+  ldy #0
+:
+  lda nb65_signature_not_found_message,y
+  beq restart
+  jsr print_a
+  iny
+  jmp :-
+  
+
 ;use C64 Kernel ROM function to read a key
 ;inputs: none
 ;outputs: A contains ASCII value of key just pressed
@@ -277,6 +314,9 @@ failed:
 ok:
 	.byte "OK ", 0
  
+ nb65_signature_not_found_message:
+ .byte "NO NB65 API FOUND",13,"PRESS ANY KEY TO RESET", 0
+ 
 dns_lookup_failed_msg:
  .byte "DNS LOOKUP FAILED", 0
 
@@ -284,3 +324,6 @@ reply_message:
   .byte "PONG!"
 reply_message_end:
 reply_message_length=reply_message_end-reply_message
+
+nb65_signature:
+  .byte $4E,$42,$36,$35  ; "NB65"  - API signature
\ No newline at end of file