type of eprom

[Peter Wales]

>I really do not understand what you're talking about with the decoder and a
>"27256", but could I use this with my MAS equipped '88 Mustang 5.0 (it's
>EECIV too)....what benefit would I gain (eg. what does this stuff do)

The Ford system is a weird setup which they have kept very much to
themselves. A few companies have cracked it and can reprogram the computer.
Hypertech probably were the first in this field and developed the procedure
and others (including us) saw what they had done and figured out our own
version of it. 

In a nutshell, the data lines are available at a connector on the rear of
the computer. There is also a feed which disables the internal eprom. The
problem was to convert the data coming from the Ford unit into something
which could be changed and the obvious answer is an Intel type EPROM. As the
early Ford units had 32k eproms, the size of the Intel device was obviously
going to be a 27256.

The challenge was to convert "Ford speak" to "Intel speak" and we used an
Actel A1010 gate array to do it. It was just about big enough (which gives
you DIY guys an idea of the size of the task you are setting yourselves) and
the latest versions have external glue logic as well. A link to the power
rail meant that by plugging it in you switched it on and by unplugging it,
it went back to the internal eprom automatically.

So we ended up with a small board which we can plug into the back of the
EECIV computer (and EEC5 if it has the port) and it will allow us to plug in
an ordinary EPROM and change the program. We have developed a device which
will read the EEC files and have most of them on record so what I am
offering is a device which will convert your EEC computer to a plug in chip
computer, then you have the job of retiming it and refuelling it to get the
best performance. It is only a converter to allow you to do the
reprogramming, in itself will do nothing for your car.

Peter Wales                    pjwales at magicnet.net
President Superchips Inc
Chairman Superchips Ltd        "Timing is everything"
Superchips home page with all the answers http://www.superchips.com