f-log

just another web log

04 Jul 2020:
once more into the vga breach dear pi
Time for another SV-3 Raspberry Pi vga update.

Powering everything off and on again with the last working settings of
dpi_group=2
dpi_mode=10


Gets me a relatively stable desktop. There are some issues.

No Blue. This will be my wiring :(
Slight ghosting at the top of the screen. The top 5th of the screen contains a ghost of the bottom 5th of the screen and is really noticeable when moving the mouse down there.

Good news is that my 640x480 display is running at a true 800x600

Next steps are to try and replicate this on the Pi Zero I soldered pins onto and to find something worthwhile to run on it.
04 Jul 2020:
you tried to scam the bank of englands manager
Been getting a lot a scam calls the last few weeks. Most have started with an automated message that Amazon is about to auto-renew your Prime account and you have to press "1" to speak to an operator to cancel. The script is always the same, they need remote access to your device to confirm the bank details.

I strung one along for a while by reading out Google Image results for the TeamViewer connection app. A number had such bad lines they gave up. But one wanted me to install TeamViewer Remote on my phone. This was easy to keep on the line, as I just kept finding other things on the App/Play store and fumbling the install.

Then today I got a good old classic "We are from BT, you have hackers on your internet, we will disconnect you". The first agent I spoke to could barely hear me and nor I him, but about 20 mins later I get another call. This one starts with the same spiel but is an automated message, "Press 1 to speak to an operator".

This conversation got a bit surreal as I got more and more frantic that the hackers had accessed my computer while I was VPN'd into work. A fictional job, where I had direct control of the Bank of England's computers. I got more and more agitated, stating that the police would need to be called as the hackers would have been able to access my account at the bank. The strange thing was that the agent kept steering call back to he needing remote connection and my bank details.

I got so flustered that I started to have panic attack, repeating that, this was major security breach and I needed to speak to my manager and police. I could hear the exasperation in his voice as he repeated that if I was not going to turn on my computer he could not get rid of the hackers :D

All these calls have been reported directly to BT.

BT scam call reporting page
01 Jul 2020:
what the resolution is that
Normal programming can return now.

We last left the Raspberry Pi Gert VGA 666 SV-3 project waiting for the battery to charge.

This is going to all be about the settings in the Pi's config.txt

Tried
dpi_group=2
dpi_mode=5


as before, no signal and it was the same for modes 6 and 7, both 640x480 resolutions. Then I tried 4 (my preferred mode previously) and then and 3. 3 actually showed a signal, but the bottom portion (about a 5th) was just static.

But, hang on, mode 3 is 720x400, time to try all the modes and groups.
dpi_group=2
dpi_mode resolution Freq. signal notes
1 640x350 85Hz No
2 640x400 85Hz Yes Bottom 5th of screen is static(*1)
3 720x400 85Hz Yes Bottom 5th of screen is static(*1)
4 640x480 60Hz No This was expected to work(*2)
5 640x480 72Hz No
6 640x480 75Hz No
7 640x480 85Hz No
8 800x600 56Hz Yes Flickery(*3)
9 800x600 60Hz Yes Flickery(*3)
10 800x600 72Hz Yes No flicker and image correctly centered
11 800x600 75Hz Yes No flicker, but image shifted to right(and lost)
12 800x600 85Hz Yes 4 copies of the mouse cursor(*4)
13 800x600 120Hz No
14 848x480 60Hz Yes Display shifted right and then wraps

(*1) Looks like about 80 pixels, rest of the display is correctly shown.
(*2) Matched what the manual said it wanted.
(*3) only on the bright whites
(*4) this is what I remember with bad resolutions and VGA monitors

dpi_group=1
dpi_mode resolution Freq. signal notes
1 VGA(*1) 60Hz No thought this would work
2 480p 60Hz No
3 480p 60Hz No (*2)
4 720p 60Hz Yes squished and shifted right
5 1080i 60Hz Yes heavy flickering and shifted bottom and left with wrap
6 480i 60Hz No
7 480i 60Hz No (*2)
8 240p 60Hz No
9 240p 60Hz No (*2)
10 480i 60Hz No
11 480i 60Hz No (*2)
12 240p 60Hz No
13 240p 60Hz No (*2)
14 480p 60Hz No
15 480p 60Hz No (*2)
16 1080p 60Hz Yes all static

(*1) VGA = 640x480
(*2) same as previous mode but 16:9 aspect ratio

OK. So it is not all the modes in both groups. There are 86 in the DMT list and another 107 in the CGA (over half of those are marked Pi 4)

So that is the end of the story to get the SV-3 to work ?

Not quite. My son asked about the SV-3 on my desk and I turned it on expecting him to see the working, but oddly coloured, desktop. Instead he saw the vertical lines.

Not sure what to do now and could non-640x480 resolutions have worked previously?
01 Jul 2020:
another test stand by
one more test
blender
linux
<<<
    >>>>
01 Jul 2020:
testing flog please stand by
So that last testing post was needed to fix the previous mess up. Where I encoded < in to &lt; but then immediately encoded that into &amp;lt;

I think I have it fixed now.
01 Jul 2020:
testing please stand by
testing
1 < 2 && 3 > 2
01 Jul 2020:
oops up side your character encoding entity
Oops! what happened in that last post ?

The f-log is still held together by random shell scripts and even a bit of Perl. This "just works" (most of the time) and I rarely touch it.

But I wanted a way of catching some of my common mistakes. Including forgetting to encode greater than, less than signs and the ampersand symbol. To add URLs and bold text I cobbled together a basic BBCode syntax.

[url title="what user sees"]actual url[/url]

A bit of regex would then rearrange that into

<a href="actual url">what the user sees</a>

Which leads us to the latest changes. I moved all html code to BBCode (-ish) for URLs, and img, code, output and em. Then I added a counting script that detects when an open tag has the accompanying closing tag.
All this allowed me to convert greater than, less than signs and the ampersand symbols into their html entities. It worked for a few posts.

The last post had a number of &nsbp; entities and they unfortunately got encoded when they should not have.

There were also some other bad encoding issues, but they were caught by the tag counting script.

Confusingly in sed the substitution part of the expression has to escape & with a backslash \& otherwise it is interpreted as a \0 (match all). All very confusing

echo "banana > orange but < tea & cake" | sed -re 's/</&lt;/gi' -e 's/>/&gt;/gi' -e 's/&/&amp;/gi'
banana >gt; orange but <lt; tea &amp; cake

which is so close

echo "banana > orange but < tea & cake" | sed -re 's/</\&lt;/gi' -e 's/>/\&gt;/gi' -e 's/&/\&amp;/gi'
banana &gt; orange but &lt; tea &amp; cake

Now this post contains a lot of <, >, and & characters so lets see how it fares.
loading results, please wait loading animateloading animateloading animate
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