Possibly the worst bit of UI in a piece of equipment still in production?
On the JPI EDM 960, there are soft keys marked “Yes” and “No” to operate the menu structure.
At one point you get “Restore Factory Settings? N”
(If you do restore factory settings, of course, you junk the whole installation and have to spend many, many hours, at €100 per hour, recalibrating – this is a certified primary instrument with all your engine gauges.)
But in order to say that you don’t want to restore factory settings you have to hit Yes. ie “Yes, I don’t want to restore factory settings.”
Where do they find the people to design these things?
They employed all those who used to design these
and who became unemployed when VCRs from from 4 bit processors to 8 bit processors 
I guess a serious answer might be that – like with 99.35% of all successful business ventures – it was a case of being in the right place at the right time with the right expertise. And if you knew how to program microprocessors in the late 1970s you were basically printing money, because everybody wanted the fancy functionality which became easy via software. I didn’t get into it until c. 1980 (and was doing it only for my company anyway) but people who were doing freelance uP product development were billing £500/day and driving Ferraris… back in the day when a Ferrari cost real money and attracted real useful attention when you parked it outside the nightclub.
Then, in aviation, those who got products certified were very well placed to hold their position. These products were never hard to design (about a man-month for the basic EDM700) or to certify but being first makes all the difference, especially if you then sue the competition into submission with bogus patents (all on google – one pointer).
Timothy wrote:
(If you do restore factory settings, of course, you junk the whole installation and have to spend many, many hours, at €100 per hour, recalibrating – this is a certified primary instrument with all your engine gauges.)
You would be advised to write down your aircraft’s settings to avoid this situation.
Timothy wrote:
But in order to say that you don’t want to restore factory settings you have to hit Yes. ie “Yes, I don’t want to restore factory settings.”
If you send a print job at my university dept. and the specified paper size doesn’t match the paper in the printer, the printer presents you with the choice of ABORT or CANCEL.
(ABORT means abort the print job, CANCEL means cancel the paper size specification and print on the paper provided.)
Where do they find the people to design these things?
I think the root of the problem is the widespread belief that taking a half-semester programming course will make you a software developer.
If you send a print job at my university dept. and the specified paper size doesn’t match the paper in the printer, the printer presents you with the choice of ABORT or CANCEL.
So there is a risk of a wasted piece of paper? Good example, but no banana. 
I have an EDM700, and so I share your pain Timothy, and perhaps it’s worse with the historic 700 compared with your shiny 960 model.
The fundamental problem with the EDM700 is that the EDM people designed the panel with just two buttons. The device then presents many different puzzles to the user beginning at start up with “Refuel y/n?” and one then has to remember which button means yes and which means no. (They are helpfully marked “Step” and “Lean find” to assist you.)…and one also has to remember the incredibly puzzling key sequence if you have added fuel (yes) but have not filled the tanks to the top (hmmm).
The system also adopts various modes of operation many of which are without any enumerated indication. These are largely accessible via a combination of long and short presses of the keys marked Step and Lean Find, despite not being step or lean find operations.
The EDM700 manual is of course rather useless, having been written or supervised by the same team that designed the panel, but sadly, unlike Toshiba laptop manuals from the 1980s, the EDM manual contains no unintended jokes good enough to leave the user gasping for air whilst laughing uncontrollably. The EDM manual is just poor.
We need to start a pressure group to get this company to start listening
Yes, the two-button user interface is horrible.
But the unit is 1980s internally. It’s the most wonderful cash cow, even by avionics standards.
Fortunately I never interact with my EDM700, after selecting the display to stay on #6, after startup. The peak find feature is fairly useless because the precision is illusory with regard to achieving best-MPG (because the SFC curve is so flat around the peak EGT point).
It is a good idea to go into Normalised Mode In the cruise. It gives you a visual alert of a stuck valve, failing ignition or preignition much earlier.
Long press on LF button, of course.
Yes; that’s a good point, if in steady cruise for a while.
Yes, Normalised mode is helpful.
I’ve decided to make my fortune by re-writing and self-publishing the manual for the EDM 700 whilst also selling little stickers to go under the two buttons with each sticker listing the various functions i.e. what each button does (yes, normalise, lean find, etc). There must be thousands of EDM700s out there.
Retirement here I come.
