Oversized EPROM's & Multiple Programs

[944Technologist]

DME stands for Digital Motor Electronics and is the same thing as ECU.

To go from 27256 to a 27512, pin 1 goes from "Vpp" which is used only in
programming to "A15". You will have to verify that the socket pin 1 is
connected to "A15". Your goal is to add an external switch that changes pin
1 from 0V to 5V. This gives you 2 banks of 256K to run different programs.
If you need to change on the fly, rig the same switch to interrupt power to
the ECU until after the bank switching has taken place.

I have to kill the ignition to switch programs. I was on an uphill grade
with the wrong gas and started to knock. So I turned off the ignition,
flipped from performance to stock program, and then restarted. 5 seconds
total. The only time I wanted to switch while on the move.

Best of luck,

FR Wilk
84 944 Porsche
______________________________________

From: "Walter Sherwin" <wsherwin at home.com>
> Thanks.  What's a DME?  When you say power down, do you mean key-off
> engine-off, then switch, then key-on and run, or simply reduce power and
> switch on the fly?  Appreciate the feedback.  My bud says thanks.......
>
>
>
> >I have a DME operating with an external switch for 2 different programs
on
> a single EPROM. One performance program and a second is the >stock
program.
> You have to power down to switch programs.
>
> >FR Wilk
> >84 944 Porsche
>
>
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