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how to connect this vfd display??


massimiliano
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hi,

as stryde has said, you need to know if your display conform to the 44780 standard. Almost all Charcter LCD's do, and most VFD's do as well. BUT be warned, some VFD's use a unique set of data instructions that MIOS will not correctly respond to.

What is printed on the circuit board? That should tell you what the part number of the modual is......

Google it from there ;)

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Hi Massimiliano,

from the pin names I´d say this display is not Hitachi compatible. Looks a lot like the old-skool parallel interface my Futaba VFD has. For the Futaba, I have written a MIOS driver. It works quite well - the only problem with my vfd is that it is quite slow. On my MBSID, using the vfd introduces an additional latency of around 2-3 ms (only for the master). I can live with it on the SID, but e.g. using it for a MBFM might or might not be possible at all.

To find out if your display has the same interface as mine, please state the exact type/manufacturer and, if you´ve found one, post a link to the data sheet. If you PM me your eMail adress, I´ll send my driver to you :)

Seppoman

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Hi,

the driver should work with this display. Just a few commands have to be changed - these parallel interfaces dont have a really standardized command set. But there´s no magic about it. I´ll put a few more comments in the source code and publish it in the next few days. Of course if Thorsten wants to put the driver on the uCApps site that would be great - I just hesitated publishing it so far because I think it would be better if someone besides me manages to get the driver to work before doing that. A few people got the driver from me in the past, but I never got any comments about the success up to now...

Seppoman

P.S. modern VFDs are mostly dot matrix displays and there are even graphical ones

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I have used them quite a bit, and they generally conform to the Hitachi standard as much as possible.

that´s not generally true. The big VFD makers (Noritake and Futaba) do build Hitachi compatible displays, but they also have old-skool parralel/serial interface displays that are cheaper than the Hitachi ones, so I suppose there are still more VFDs in action and on sale that are not compatible. The one from Massimiliano is one of these.

Seppoman

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seppoman, you talked about a slow response of your vfd display... will this delay affect even the sound of my sid?

However, if you can send me your driver within an e-mail i'll try to connect all. but be patient, since i'm a newbie not so expert in electronixx, could you send me an interconnection diagram for the pinning? will i have to power my vfd separately of the core will send the power to it?

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  • 2 weeks later...

Do you have any of this boatload for sale, MRE? :)

Well shizzle.. I wasnt expecting that, but sure. I havn't counted lately, but if memory serves, I have like 20 or 30!  ;)

They are all only slightly used, as the undisclosed location from which I got them had done a major upgrade to 500 machines. About 200 of them needed side cars because they were way too old to install the imbedded version of the upgrade. Within 5 months, most of those machines were subsequently replaced with the imbedded units already installed. So.. long story short, 200 side cars went in the trash. Dumpster diving never hurt anyone!

(I'm just kickin myself for not saving the 10 digit keypads and card readers!)

Last I checked, the street price for a 20x2 VFD was between $50 and $90. Naturally I would not demand nearly that. How does $25 plus shipping sound?

I can give a link to the data sheet. I have used the standard Hitatchi startup routines (and ran both 4 bit and 8 bit modes) with no problems but check the special fuctions and charactor sets to be sure.

Comes with a short cable (1.5 inch?) that has a connector on both ends. The pins are two rows of I think 6 rather than one long row.

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Hi,

sorry for the long delay - I was on vacation...

But today I finished an updated version of the driver with small bugfixes, more documentation and a workaround for the missing "custom character" capability of the display. Here we go:

http://www.seppoman.de/vfd/

seppoman, you talked about a slow response of your vfd display... will this delay affect even the sound of my sid?

Actually the "slow" response is not visible, it does only slightly affect the timing of the SID (my VFD introduces an additional latency/jitter of around 2 ms). You probably won´t notice this at all.

However, if you can send me your driver within an e-mail i'll try to connect all. but be patient, since i'm a newbie not so expert in electronixx, could you send me an interconnection diagram for the pinning? will i have to power my vfd separately of the core will send the power to it?

All information about pinning is in the header of the source code.

If you use the voltage regulator on the core you should probably power the VFD separately. It takes about 700 mA, you would need a large heatsink. If you´ve built the MBSID PSU optimized cirquit, you can use the normal 5V supply - the C64 PSU is rated 1.5 A at 5 V.

As compensation for your long wait I´ve made a "starting point" version of the driver for you. It *could* work for the Noritake as is. Noritake doesn´t give out detailed data sheets, so there´s no exact description e.g. about cursor position count. here is the download: http://www.seppoman.de/vfd/app_lcd_noritake.zip

Kind regards,

Seppoman

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Hey Seppo,

Thanks for posting your driver. I just got a IEEE VFD - it's pins are labeled:

D0-D7 (of course)

Busy

Write Strobe

Reset

+5

Ground

These are slightly different that the ones in your driver:

; ==========================================================================

;

;      connections:

;

;      core module ->  display

;

;      D0..D7      ->  D0..D7

;      Enable      ->  SEL#

;      R/W        ->  WR#

;      R/S        ->  BUSY (plus a 100 Ohm resistor in series !!!)

;      N/C or +5V  ->  TEST#

;

; ==========================================================================

Would it be possible for me to use this driver as a starting point? If so what would the connections be?

Thanks,

Justin

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Busy is Busy, Write Strobe is the same as WR# (don´t know if it´s low or high active so if nothing happens you could try to exchange bcf and bsf at the lines concerning WR. Reset? you´ll have to tie this either to GND or 5V. You don´t have a SEL line. This just means you can´t connect more than one display to the same port. You could delete the lines concerning the SEL line out of the driver, or just ignore it. All this is in User_LCD_Data.

But anyway, you´ll have to find a data sheet to learn about the special commands of the display. Without it you´ll have a hard time finding out how to position the cursor etc.

Seppoman

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  • 2 months later...

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