[ischmitz]

The "bahavior" is entirely in the EPROM and not the DME itself. The other hardware in the DME is identical throughout the years with only one exception: The early Porsche DME had one half of the code on the MCU (main processor) and the other half that is car-specific on a 4k external EPROM (chip) while the later DME uses an 8k extenal EPROM (chip) to store the complete code. You can tell the difference by counting the legs on the EPROM:

- 4k EPROM has 24 legs
- 8k EPROM has 28 legs

The modification from early to late can be made quite easily by extending the socket for the EPROM, adding a jumper and inserting the late EPROM. So in summary converting your DME into the latest version is really straight forward.

Once you do that you might have to adjust your throttle stop a little bit since the base idle speed was changed in the later code.

Best
Ingo