NIStune Type 1 Diagnostics - Manual (Page 13)

7. When I try to make a change to the maps, tables or constants and then disconnects
Type 1 Rev A/B boards only
This means that Nistune has attempted to write to your onboard NVRAM device or Romulator, but either during
the write to the device or the read back verify by the ECU patch code, there was a failure.
Check that you have the correct offset and length specified in your address file
OFFSET=&H8000
LENGTH=&H4000
If you are using a Pocket Romulator or similar emulator, ensure that the emulator is selected in the File -
Configuration screen and the Emulator button is enabled (it changes RED when enabled). All updates when the
emulator is selected will be performed to the emulator