[Coco] [SPAM] Re: [SPAM] [SPAM] Re: Cross Post from the Facebook Page about the RGB2VGA Board

John B trymyz at gmail.com
Sat Jul 11 00:53:41 EDT 2015


Thanks Steve.  Yeah something isnt right when I program the .jic vs .sof.
Don't get me wrong it works, but it just doesnt show the test pattern.  I
will mess with it some more.

On Sat, Jul 11, 2015 at 12:43 AM, Steve Batson <steve at batsonphotography.com>
wrote:

> John,
>
> I had to copy everything from Luis' code I downloaded to a folder that the
> software used and then use it to program the board. I don't recall the
> steps, but it did work the first time I got my convert hard plugged in. And
> yes, when the CoCo is off, it displays a default test pattern built in to
> the FPGA software.  When I turn the CoCo on, it goes to the CoCo screen.
> Something doesn't sound right with what you are seeing though. You may have
> to play with getting the FPGA programmed, those don't have anything to do
> with the card.
>
>
>
>
>
> On Jul 10, 2015, at 9:28 PM, John B <trymyz at gmail.com> wrote:
>
> > Interesting.  When I used the .jic from Github I would no longer get the
> > test pattern when the CoCo was off so I just compiled my own.  Now it
> > behaves just like the .sof..  The .jic from github would just display a
> > previous CoCo image (somewhat garbled) when the power was off.  Do you
> > experience the same thing when the CoCo is off and the monitor is on?
> >
> > On Sat, Jul 11, 2015 at 12:23 AM, Steve Batson <
> steve at batsonphotography.com>
> > wrote:
> >
> >> I used the .JIC file. Roger had issues with compiling the code and Luis
> >> said it wasn't the same version and that the compiled version had some
> >> fixes.
> >>
> >> On Jul 10, 2015, at 7:59 PM, John B <trymyz at gmail.com> wrote:
> >>
> >>> Steve,
> >>>
> >>> I still have the recommended resistor values from Luis' design.
> >>> Unfortunately no one locally has the values you recommended so I am
> >> placing
> >>> my DigiKey order tonight.  I will just create another board since I
> have
> >> 2
> >>> spares.  Then I can really compare the two.  I have taken care of
> >>> recommendations 1-3.  I will pull that wire tonight.  Also, did you use
> >> the
> >>> .sof and/or .jic from Luis' Github page?
> >>>
> >>> On Fri, Jul 10, 2015 at 10:39 PM, Steve Batson <
> >> steve at batsonphotography.com>
> >>> wrote:
> >>>
> >>>> John,
> >>>>
> >>>> Have you changed the resistors yet, or are you using the resistors
> >>>> recommended for the design? I was seeing jitter, where the entire
> screen
> >>>> would jerk and occasional waves going through it mostly noticeable on
> >> the
> >>>> edges. Also, it didn't seem consistent, sometimes it was worse than
> >> others.
> >>>> Based on what Roger had found, it sounded like there were a number of
> >>>> issues being caused by the original resistor values. Voltage Levels
> were
> >>>> not what they should be. Also there was issues with the HSYNC and
> VSYNC
> >>>> again caused by original resistor values. Luis and posted on the FB
> >> page a
> >>>> response to one of my questions that some CoCo's are noisier than
> others
> >>>> and this may very well be true, but I'd guess symptoms could be worse
> on
> >>>> some systems then others which could be the combination of the CoCo
> and
> >>>> Monitor. From discussions with Roger about this and how he fixed it,
> I'm
> >>>> going to go out on a limb here and suggest that with his suggested
> >> resistor
> >>>> values, the video will most likely be crisp, clean and jitter free on
> >> most
> >>>> any CoCo and VGA monitor unless they have problems of their own.
> >>>>
> >>>> It was a bit of a pain in the butt pulling a bunch of resistors out
> and
> >>>> replacing them with Rogers suggested values, but I'd highly recommend
> >> it if
> >>>> you haven't done so already. It was totally worth it! If you have
> >> already
> >>>> replaced the resistors with the new values and are still having
> issues,
> >> I'd
> >>>> suggest the following:
> >>>>
> >>>> 1) Inspect your board and make sure you have no possible shorts. Clean
> >> it
> >>>> real good with alcohol or other good electronic board cleaner and
> >>>> thoroughly dry.
> >>>> 2) Check all the cables including power going to the board and make
> sure
> >>>> all is well
> >>>> 3) Make sure the ribbon cable isn't right next to a transformer
> >> including
> >>>> the CoCo power power supply (thought I am not having issues even if
> set
> >> the
> >>>> board right on top of the CoCo above the transformer). This probably
> is
> >> NOT
> >>>> an issue.
> >>>> 4) Remove wire I mentioned that was a ground fix.
> >>>>
> >>>> Anyway, let me know if you have changed the resistors yet or not. I'm
> >> very
> >>>> curious to see where you are at.
> >>>>
> >>>>
> >>>> On Jul 10, 2015, at 7:18 PM, John B <trymyz at gmail.com> wrote:
> >>>>
> >>>>> Steve,
> >>>>>
> >>>>> I tested the board out.  The display comes out fine, colors display
> >>>>> properly, etc.  However, the edge of any line looks slightly wavy.
> >>>> Hardly
> >>>>> noticeable.  This is more evident with graphics opposed to text.  Of
> >>>> course
> >>>>> I played with the trim pot, but that only helped so much.  Is this
> what
> >>>> you
> >>>>> experienced before u swapped the resistors?
> >>>>>
> >>>>> On Fri, Jul 10, 2015 at 11:36 AM, Steve Batson <
> >>>> steve at batsonphotography.com>
> >>>>> wrote:
> >>>>>
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>> No problem, Roger deserves the credit all this work. I just
> duplicated
> >>>>>> what he did and putting info here hoping it's helpful.
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>> I had no stock of resistors and trying to find just a few either
> >> wasn't
> >>>>>> economical or easy. Needless to say, I've got a pretty good stock
> now!
> >>>>>> :D
> >>>>>>
> >>>>>>> Thank you very much Steve. I should be able to
> >>>>>> test it out today. I will
> >>>>>>
> >>>>>>> report back either way. I might put my DigiKey order in anyway. You
> >>>>>> can
> >>>>>>
> >>>>>>> never have too many resistors :)
> >>>>>>
> >>>>>>>
> >>>>>>
> >>>>>>> On Fri, Jul 10, 2015 at 9:07 AM, Steve Batson
> >>>>>>
> >>>>>>> <steve at batsonphotography.com>
> >>>>>>
> >>>>>>> wrote:
> >>>>>>
> >>>>>>>
> >>>>>>
> >>>>>>>> John,
> >>>>>>
> >>>>>>>>
> >>>>>>
> >>>>>>>> No, the resistor from R7 to Pos 8 on the GPIO1 connector is what
> >>>>>> was
> >>>>>>
> >>>>>>>> referred to as Rx, that resistor should be 1.8K. The drawing on
> >>>>>> Luis'
> >>>>>>
> >>>>>>>> site
> >>>>>>
> >>>>>>>> shows a jumper wire to fix a ground issue. If that jumper is in
> >>>>>> place
> >>>>>>
> >>>>>>>> after
> >>>>>>
> >>>>>>>> all the resistors in place, you will most likely have Jitter.
> >>>>>> There
> >>>>>>
> >>>>>>>> should
> >>>>>>
> >>>>>>>> be no Jumper wires installed. The jumper Luis refers to is
> >>>>>> between R21
> >>>>>>
> >>>>>>>> and
> >>>>>>
> >>>>>>>> R18. I'd only install that if Jitter is present with all the
> >>>>>> resistor
> >>>>>>
> >>>>>>>> changes. If necessary, try it both ways, but on Roger and my
> >>>>>> board it
> >>>>>>
> >>>>>>>> wasn't necessary. All of these changes were Roger's findings. I
> >>>>>> only
> >>>>>>
> >>>>>>>> duplicated his setup and it's awesome!
> >>>>>>
> >>>>>>>>
> >>>>>>
> >>>>>>>>
> >>>>>>
> >>>>>>>>
> >>>>>>
> >>>>>>>> On Jul 9, 2015, at 10:22 PM, John B <trymyz at gmail.com>
> >>>>>> wrote:
> >>>>>>
> >>>>>>>>
> >>>>>>
> >>>>>>>>> I will be testing it tomorrow. Thank you for the new
> >>>>>> values.
> >>>>>>
> >>>>>>>> Hopefully
> >>>>>>
> >>>>>>>>> everything will work as intended. You refer to the
> >>>>>> additional wires
> >>>>>>
> >>>>>>>> not
> >>>>>>
> >>>>>>>>> being needed. Is this the resistor from R7 to Position 8 on
> >>>>>> GPIO1 and
> >>>>>>
> >>>>>>>> the
> >>>>>>
> >>>>>>>>> wire between R18 and R21?
> >>>>>>
> >>>>>>>>>
> >>>>>>
> >>>>>>>>> On Fri, Jul 10, 2015 at 12:56 AM, Steve Batson <
> >>>>>>
> >>>>>>>> steve at batsonphotography.com>
> >>>>>>
> >>>>>>>>> wrote:
> >>>>>>
> >>>>>>>>>
> >>>>>>
> >>>>>>>>>> John,
> >>>>>>
> >>>>>>>>>>
> >>>>>>
> >>>>>>>>>> Yes, this is Luis' RGB2VGA board used with the DENano
> >>>>>> FPGA.
> >>>>>>
> >>>>>>>>>>
> >>>>>>
> >>>>>>>>>> Since you have just finished it, I'd test it out first
> >>>>>> to see if you
> >>>>>>
> >>>>>>>> see
> >>>>>>
> >>>>>>>>>> any jitter or other problems. However Roger did a lot
> >>>>>> of
> >>>>>>
> >>>>>>>> investigation
> >>>>>>
> >>>>>>>> and
> >>>>>>
> >>>>>>>>>> found these values produce voltages in line with the VGA
> >>>>>> Standard and
> >>>>>>
> >>>>>>>> to
> >>>>>>
> >>>>>>>>>> help the board properly sync from the CoCo output. I
> >>>>>> don't have all
> >>>>>>
> >>>>>>>> the
> >>>>>>
> >>>>>>>>>> technical details, I just know it worked for Roger and
> >>>>>> works for me.
> >>>>>>
> >>>>>>>>>>
> >>>>>>
> >>>>>>>>>> These are what Roger came up with and I simply
> >>>>>> duplicated what he
> >>>>>>
> >>>>>>>> found.
> >>>>>>
> >>>>>>>>>> Also, the Variable resistor, he recommended a 10K Multi
> >>>>>> Turn for
> >>>>>>
> >>>>>>>> finer
> >>>>>>
> >>>>>>>>>> control when tuning for the best appearance. Another
> >>>>>> thing to know is
> >>>>>>
> >>>>>>>> that
> >>>>>>
> >>>>>>>>>> there are some additional wires recommended but they
> >>>>>> were not needed
> >>>>>>
> >>>>>>>> on
> >>>>>>
> >>>>>>>>>> Roger's or my case and jitter did not go away until
> >>>>>> removed.
> >>>>>>
> >>>>>>>>>>
> >>>>>>
> >>>>>>>>>> Top Left
> >>>>>>
> >>>>>>>>>>
> >>>>>>
> >>>>>>>>>> 82 Ohms - Grey-Red-Black-Gold-Brown
> >>>>>>
> >>>>>>>>>> R22
> >>>>>>
> >>>>>>>>>> R23
> >>>>>>
> >>>>>>>>>> R25
> >>>>>>
> >>>>>>>>>>
> >>>>>>
> >>>>>>>>>> * * * Bottom Left
> >>>>>>
> >>>>>>>>>>
> >>>>>>
> >>>>>>>>>> 1.2K Brown-Red-Black-Brown-Brown
> >>>>>>
> >>>>>>>>>> R18
> >>>>>>
> >>>>>>>>>> R19
> >>>>>>
> >>>>>>>>>> R20
> >>>>>>
> >>>>>>>>>> R21
> >>>>>>
> >>>>>>>>>>
> >>>>>>
> >>>>>>>>>> * * * Top Right 10
> >>>>>>
> >>>>>>>>>>
> >>>>>>
> >>>>>>>>>> R9 47
> >>>>>>
> >>>>>>>>>> R10 47
> >>>>>>
> >>>>>>>>>>
> >>>>>>
> >>>>>>>>>> 390 ohms
> >>>>>>
> >>>>>>>>>> R1
> >>>>>>
> >>>>>>>>>> R4
> >>>>>>
> >>>>>>>>>> R7
> >>>>>>
> >>>>>>>>>>
> >>>>>>
> >>>>>>>>>> 820 ohms
> >>>>>>
> >>>>>>>>>> R2
> >>>>>>
> >>>>>>>>>> R5
> >>>>>>
> >>>>>>>>>> R8
> >>>>>>
> >>>>>>>>>>
> >>>>>>
> >>>>>>>>>> 1.8K ohms
> >>>>>>
> >>>>>>>>>> R3
> >>>>>>
> >>>>>>>>>> R6
> >>>>>>
> >>>>>>>>>> Rx (this is the resistor soldered to R7 and the GPIO1
> >>>>>> Connector)
> >>>>>>
> >>>>>>>>>>
> >>>>>>
> >>>>>>>>>> * * * Bottom Right
> >>>>>>
> >>>>>>>>>>
> >>>>>>
> >>>>>>>>>> 2K Red-Black-Red-Gold
> >>>>>>
> >>>>>>>>>> R17
> >>>>>>
> >>>>>>>>>> R14
> >>>>>>
> >>>>>>>>>> R12
> >>>>>>
> >>>>>>>>>> R11
> >>>>>>
> >>>>>>>>>>
> >>>>>>
> >>>>>>>>>> 1K Brown-Black-black-Brown-Brown
> >>>>>>
> >>>>>>>>>> R15
> >>>>>>
> >>>>>>>>>> R16
> >>>>>>
> >>>>>>>>>>
> >>>>>>
> >>>>>>>>>>
> >>>>>>
> >>>>>>>>>>
> >>>>>>
> >>>>>>>>>>
> >>>>>>
> >>>>>>>>>> On Jul 9, 2015, at 9:31 PM, John B
> >>>>>> <trymyz at gmail.com> wrote:
> >>>>>>
> >>>>>>>>>>
> >>>>>>
> >>>>>>>>>>> Steve,
> >>>>>>
> >>>>>>>>>>>
> >>>>>>
> >>>>>>>>>>> Are you referring to Luis' RGB2VGA board? The reason
> >>>>>> I ask is I
> >>>>>>
> >>>>>>>>>> literally
> >>>>>>
> >>>>>>>>>>> (15 min ago) just finished assmebling my board. I
> >>>>>> used the
> >>>>>>
> >>>>>>>> resistors
> >>>>>>
> >>>>>>>> he
> >>>>>>
> >>>>>>>>>>> outlined on his page under the
> >>>>>> "Modifications" section.
> >>>>>>
> >>>>>>>>>>> https://sites.google.com/site/tandycocoloco/rgb2vga
> >>>>>> Are those the
> >>>>>>
> >>>>>>>>>>> resistors that produced the video jitter? If so, can
> >>>>>> you give us
> >>>>>>
> >>>>>>>> the
> >>>>>>
> >>>>>>>> new
> >>>>>>
> >>>>>>>>>>> values that fixed the issue?
> >>>>>>
> >>>>>>>>>>>
> >>>>>>
> >>>>>>>>>>> Thanks,
> >>>>>>
> >>>>>>>>>>>
> >>>>>>
> >>>>>>>>>>> John
> >>>>>>
> >>>>>>>>>>>
> >>>>>>
> >>>>>>>>>>> On Thu, Jul 9, 2015 at 11:45 PM, Steve Batson
> >>>>>> <
> >>>>>>
> >>>>>>>>>> steve at batsonphotography.com>
> >>>>>>
> >>>>>>>>>>> wrote:
> >>>>>>
> >>>>>>>>>>>
> >>>>>>
> >>>>>>>>>>>> I figured I'd post the following here too. Some
> >>>>>> discussion occurred
> >>>>>>
> >>>>>>>> on
> >>>>>>
> >>>>>>>>>> the
> >>>>>>
> >>>>>>>>>>>> FB page, but a lot of discussion was done
> >>>>>> between Roger and Myself
> >>>>>>
> >>>>>>>> in
> >>>>>>
> >>>>>>>>>> email
> >>>>>>
> >>>>>>>>>>>> as Roger made several discoveries that
> >>>>>> stabilized some very
> >>>>>>
> >>>>>>>> annoying
> >>>>>>
> >>>>>>>>>> jitter
> >>>>>>
> >>>>>>>>>>>> problems with video.
> >>>>>>
> >>>>>>>>>>>>
> >>>>>>
> >>>>>>>>>>>> RGB2VGA Stabilized!
> >>>>>>
> >>>>>>>>>>>> First thanks to Felipe for a very cool Solution
> >>>>>> to bring the CoCo3
> >>>>>>
> >>>>>>>> video
> >>>>>>
> >>>>>>>>>>>> to Modern VGA Monitors. Originally, I missed a
> >>>>>> few resistors that I
> >>>>>>
> >>>>>>>>>> somehow
> >>>>>>
> >>>>>>>>>>>> thought were optional and Felipe straightened me
> >>>>>> out on those.
> >>>>>>
> >>>>>>>>>>>> Then I was getting Jitter just like Roger was
> >>>>>> experiencing. I had
> >>>>>>
> >>>>>>>>>> several
> >>>>>>
> >>>>>>>>>>>> email discussions with Roger as he was doing
> >>>>>> some research and
> >>>>>>
> >>>>>>>>>>>> experimenting based on what he found about the
> >>>>>> VGA standards and
> >>>>>>
> >>>>>>>> found
> >>>>>>
> >>>>>>>>>> that
> >>>>>>
> >>>>>>>>>>>> changing some resistor values stabilized the
> >>>>>> output from his board.
> >>>>>>
> >>>>>>>> I
> >>>>>>
> >>>>>>>>>> have
> >>>>>>
> >>>>>>>>>>>> pretty much duplicated Roger's resistor values
> >>>>>> on my board with the
> >>>>>>
> >>>>>>>>>>>> exception of 4 that I'm waiting to come in, but
> >>>>>> mine is crisp and
> >>>>>>
> >>>>>>>>>> jitter is
> >>>>>>
> >>>>>>>>>>>> gone. I will most likely change those 4
> >>>>>> resistors when the parts
> >>>>>>
> >>>>>>>> come
> >>>>>>
> >>>>>>>> in
> >>>>>>
> >>>>>>>>>>>> unless it doesn't make sense.
> >>>>>>
> >>>>>>>>>>>> Anyway, Finally fantastic output on my VGA
> >>>>>> monitor. Very Cool!!!
> >>>>>>
> >>>>>>>>>>>> Very Big thanks to Roger!!!
> >>>>>>
> >>>>>>>>>>>>
> >>>>>>
> >>>>>>>>>>>> --
> >>>>>>
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> >>>>>>
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> >>>>>>
> >>>>>>>>>>>>
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> >>>>>>
> >>>>>>>>>>>>
> >>>>>>
> >>>>>>>>>>>
> >>>>>>
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> >>>>>>
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> >>>>>>
> >>>>>>>>>>> https://pairlist5.pair.net/mailman/listinfo/coco
> >>>>>>
> >>>>>>>>>>
> >>>>>>
> >>>>>>>>>>
> >>>>>>
> >>>>>>>>>>
> >>>>>>
> >>>>>>>>>> --
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> >>>>>>
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> >>>>>>
> >>>>>>>>>>
> >>>>>>
> >>>>>>>>>
> >>>>>>
> >>>>>>>>> --
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> >>>>>>
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> >>>>>>>>
> >>>>>>
> >>>>>>>> --
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> >>>>>>
> >>>>>>>
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>> --
> >>>>>>
> >>>>>> Steve Batson
> >>>>>>
> >>>>>> Website: http://www.batsonphotography.com
> >>>>>>
> >>>>>> Facebook:
> >>>>>> https://www.facebook.com/pages/Batson-Photography/313748145356
> >>>>>>
> >>>>>> Gallery: http://gallery.batsonphotography.com
> >>>>>>
> >>>>>> --
> >>>>>> Coco mailing list
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> >>>>>>
> >>>>>
> >>>>> --
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> >>>>
> >>>>
> >>>>
> >>>> --
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> >>>>
> >>>
> >>> --
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> >>
> >>
> >>
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> >>
> >
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>
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