[Techtoolslist] Looking for a 9100A VFD display

[Andre Huijts]

Hi John,
Yes I am aware it’s a DMD but the vast bulk of info displayed by the 9100A is simply text or inverse text.
From what I’ve read in the manuals it says something else. It says the main unit puts out the characters in codes as per a table which is also in the manual.

I looked up the code for the capital A and it’s 41 hex and 65 decimal, and I remember that that is the ASCII code for A from my (Atari) BASIC programming days…

Anyway, these codes are sent by the main board to U1 (the Z8 on the display board). The Z8 translates this into the pattern that is needed to be displayed.

Of course the display can also do some graphics (although…..where does the 9100A do that ?) but the table says it sends a certain code and then the next 6 bytes contain the graphics. Stuff like that would be needed to decoded and translated if we’d use another display device.

Maybe some of the newer serial VFD displays actually understand these commands….that’s why I’d like to compare the current manuals of those with the old one.

Anyway, as a first step, you could hook up the serial pins of the display connector to a computer with a terminal program to see what data is “spit out” by the main board.
Not sure if a MAX-232 is needed to get stuff to real RS-232 level…or maybe some optical separation for safety ? 


I couldn’t find the interface nor the 70V generation section (not even the fuse) on the manuals…..anyone have a tip where they are ? 

Cheers, André




> Op 17 aug. 2015, om 23:37 heeft John Robertson <jrr at flippers.com> het volgende geschreven:
> 
> Hi Andre,
> 
> The DM256X26GB tube is just a Dot Matrix Display (DMD) tube - it can display anything within the  restrictions of 256 column by 26 row variable intensity matrix. It is the video interface board that you need to decode.
> 
> John :-#)#
> 
> On 08/17/2015 1:54 PM, Andre Huijts wrote:
>> Thanks for the replies guys !
>> 
>> Yes it would be awesome if a replacement could be made. From what I’ve read the characters are sent by the main unit in ASCII format (well at least part of the character set) at 19.2 kbd in TTL RS-232 format.
>> 
>> I think there are plenty of LCD displays with serial interfaces but finding one with the right size might be tricky.
>> 
>> It would be great if we had the technical datasheet of the DM256X26GB as it shows which characters it “understands”.
>> 
>> I found displays of the same brand with serial interface and some more lines on the display, but I wouldn’t be bothered by that.
>> 
>> Alternatively, it would be a nice arduino project I guess. It could do some translation to a TFT full color display….the only problem is fitting one in the unit…..or loose the “Softkeys” direct relation with a remote display.
>> 
>> I’m still a bit amazed that Fluke didn’t make an option to use the monitor output instead of the internal display for regular test work.
>> 
>> 
>> 
>> Anyway….the thing that bothers me is that I cannot SEE a phyical damage on the VFD. If there would be a crack it would be sure enough it was dead.
>> 
>> So I did some measuring and found that the 70V that is required for the display is missing….
>> 
>> Now I have to find out how this voltage is generated….pretty sure it’s not coming directly from the power supply as it’s a weird voltage…
>> 
>> Diving into the docs now…
>> 
>> There may be some hope….
>> 
>> Cheers, André
>> 
>> 
>> 
>>> Op 17 aug. 2015, om 21:24 heeft John Robertson <jrr at flippers.com> het volgende geschreven:
>>> 
>>> It is likely time for someone to make an LCD/LED replacement...
>>> 
>>> I did find spare NOS displays on eBay years ago, might still be available there (not at the moment though). Noritake Itron DM256X26GB (21B)
>>> 
>>> So, it is 256 X 26 DMD
>>> 
>>> Noritake-Itron does still supply all sorts of displays - perhaps one of their old distributors may have one lying around?
>>> 
>>> 
>>> John :-#)#
>>> 
>>> On 08/17/2015 11:53 AM, William Stillwell wrote:
>>>> I ended up buying another 9110FT as nobody had a spare VFD display, I have the board, but no VFD Glass, but it’s a LOT of pins to remove a VFD, maybe you just damaged IC or broke a part off PCB?
>>>> 
>>>> William Stillwell
>>>> Hamster / KI4SWY
>>>> Stillwell Software Solutions.
>>>> Free Play Florida Arcade & Pinball Show Organizer
>>>> 
>>>> -----Original Message-----
>>>> From: Techtoolslist [mailto:techtoolslist-bounces at flippers.com] On Behalf Of Andre Huijts
>>>> Sent: Monday, August 17, 2015 1:51 AM
>>>> To: Technical Tools Mail List <techtoolslist at flippers.com>
>>>> Subject: [Techtoolslist] Looking for a 9100A VFD display
>>>> 
>>>> Oh no..... ;( looks like the VFD display on my 9100A has dies and the worst of it is that it's my own bloody stupid fault....the front of my 9100A was pretty loose because of others before me opening it not so carefully and the plastic "clips" probably becoming a bit more brittle over the years.
>>>> I had put away the unit on about 1 meter high and somehow the front part got completely loose and dropped on the floor......the ribbon cable came loose in the process.
>>>> 
>>>> I think it is correct that one corner pin is clipped off from this connector ? it is on both sides as far as I can see.
>>>> 
>>>> Removed the VFD PCB but can't see any visible problem. I assume I should see some glow at the "bulb" end of the VFD ?
>>>> 
>>>> So....if anyone has a working VFD display for me please let me know.
>>>> 
>>>> André
> 
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André Huijts
andre.huijts at upcmail.nl