Real Honeywell MCDU in PSX

[744sim]

Hi all,

I'm working on my genuine Honeywell MCDU and I wonder if anyone has succeeded in giving life to original cathode ray tube (CRT) displays from a PC video card. I'm very interested in this point and I would welcome any information and help about this issue.

Thanks in advance,

[the mad hatter]

Sorry bud.. not to rain on your idea .. what you  want to do is the holy grail for sim builders ..me included .. you can get the CDU CRT to function if you use the aircraft computers.. however.. how do you update the navigation data base etc .you would need the airborne unit etc etc nightmare job ..and even then they will not talk to PSX. the easiest thing to do is convert the CRT to a LCD and live with that... however that being said there is a Japanese chap on this forum that has the CRT operational in his sim .bit he purchased this from a simulator that was already converted ..he might allow for that card in there to be reversed engineered nd I for one eould contribute to that as I would need 3 for CDUS and x6 for the MIP

[farrokh747]

I believe the CRT is made by:

http://www.thomaselectronics.com/avionics/multi-function-display/

http://www.thomas-global.com/www/content/default.aspx?cid=817&fid=815

You'll have to get a stand-alone High Voltage, G2 Voltage and Focus Voltage power supply, and then have someone design a card that can convert VGA into a Horizontal and Vertical deflection signal for the yoke..... basically, we're trying to run an old tube-TV from VGA  -

If there's someone in your area who has experience from the tube days, it may be possible to do, but it will cost....

I dont think it's realistic to use the OEM CDU as is, with the high number of arinc data streams it needs to work...

fc

[Mark]

From the first post, it looks like Javier just wants to reuse the CRT from the MCDU rather than the internal processor which is sensible.

I'm assuming that the MCDU graphics are vector drawn rather than raster scanned (does anyone know?).
So I would approach the hypothetical challenge like this:

- Power up the CRT with the correct high voltage (this is extremely dangerous, severe caution would be required as presumably at this point the CRT isn't in a proper enclosure).
- Use the deflection amplifiers from a CRT oscilloscope (preferably with intensity control) and calibrate the amplifiers to fit the new display. Could probably also use the HV source?
- Drive the deflection amplifiers either from a microcontroller with 2 DACs or a PC soundcard.
- Write an app that takes in the Qs display strings and draws a vector path to output to the deflection amplifiers.

It does seem like a lot of effort however I've yet to see an aftermarket CDU that has a really great contrast ratio (unfortunately LCDs small enough for a CDU aren't usually panels with superb contrast and viewing angle specifications). I'm really waiting for OLED panels to become available to get the quality of screen we all deserve.

[Roddez]

When we were developing the SimStack MCDU, we looked at ways of retaining the real CRT.  However due to complexity, voltage and price we decided to substitute an LCD unit.

As some of you may be aware, we do have a small number of converted 747-400 MCDU's available for sale.
https://simulatorsolutions.com.au/simstack/simstack-mcdu/

We can also supply a conversion kit for people who have an existing MCDU they wish to use with PSX.  The conversion kit contains all the parts needed to convert a real 747 MCDU for use with PSX.  Whist this does use an LCD display, we have found that the results to be very true to the original unit.  Our conversion kit also uses green tinted glass in front of the screen to provided added effect.

Finally, we do have a function available where power to the LCD is switched off when the corresponding screen in PSX is off.  This means that in a "cold and dark" scenario, the MCDU is truly cold and dark.

If you would like more information, please drop me a note through the forum.