Let's talk about EFI user interfaces.
Back in 1975 the first computer I designed, built and sold had
four on and off toggle switches. You chose one of 16 programs
in the computer ROM you wanted to run by looking it up in a printed
table and setting the four switches on or off in the combination
that corresponded to the program you wanted to run.
Then you pressed the go button. The Kim 1 had a better user interface.

Then the Apple II came on the market with a full qwerty keyboard
and a 40 character wide CRT. You typed the name of the program
and pressed return. This was called the command line.
A major advance in users interfaces over flipping toggle switches.
People still wanted more.

Than Apple finally came out with a 80 character display.
People wanted more. Then the Mac came out with a graphic  interface
where you choose labeled buttons or hieroglyphic like icons to push
on the screen with a mouse pointer. This was called a Graphic User Interface or
GUI for short.  That is basically what we still have to this day with Windoze.

The vast majority of after market EFI computers use a USB interface to a full
PC computer with a Graphic User Interface program to tune the fuel injection map. This
includes the MegaSquirt and the Data Acquisition system I just bought for $80.
This is simple and straight forward. Easy to under stand and easy to use because
everybody that uses a computer is familiar with it. One glance at the screen and you
can see the mixture value anywhere in the map and it is simple and fast to change
or edit. The more keys you have to work with and the higher the resolution
of the screen the better the user interface.

Tracy decided not to do this as he had an RV4 and there was no room in the
cockpit for a notebook computer. His user interface to this day consist of a
few switches and a few characters on a LCD. Pretty much the same I as I was
doing back in 1975. Therein lies the gist of the EFI tuning problem IMHO.


Paul Lamar