Showing posts with label issues. Show all posts
Showing posts with label issues. Show all posts

Thursday, May 19, 2022

Terra Luna and UST crash, what really happened--Anchor, Luna, UST bankrupted.



* Many people in TerraLuna reddit believe it's an attack. Partly because Luna CEO kept saying 'attack' in revival plan. But if you can at least see below chart, you will understand how withrew UST from Anchor was act of attack. 

Many people thinks that this is stablecoin (or algorithmic stablecoin) problem or crypto coin's problem. Or even call an attack. But if you dig up deeper, it was completely different case--it was Ponzi scheme or even fraud.

They pumped the price of Luna and then converted it to UST--which led to printed more UST than what they really are. People pumped price(for buying Luna), too--I guess. Because Anchor's 20% APY interest rate.


I didn't know much about the Luna and UST crypto coin before. And when the crash was happening, I did some dig up and it took quite some time to understand because it was quite complicated things there--I have to know more about the Luna, UST, stablecoin, algorithmic stablecoin and Anchor protocol.

So I might be wrong about the details but I think my main questioin was right.

I thought about explain what I've learn but things were complicated because it involved with Luna, UST, stablecoin--algorithmic stablecoin and Anchor.

So I will just show you the one chart which I believe I can simplfy main question--where is 10 to 12 billions worth of US dollars(UST)?


That's why LFG(Luna Foundation Guard), Luna and UST were bankrupted--it was just simplification for easy understanding.

Total deposit and borrow on Anchor protocol chart from CoinDesk Rearch, Anchor Protocol Dashboard

Total deposit and borrow on Anchor protocol chart and quoted from The LUNA and UST Crash Explained in 5 Charts @ May 11, 2022 By Sam Kessler, Sage D. Young

About 10 billions of UST was withdrew from the Anchor protocol in 4 days.

As you can see in the chart, people withdrew UST from Anchor. About 10 billions of UST within 4 days which goes to the market to sell their coins.

So much coins were goes to the market which make many people believed that it was an attack.

But I don't think it was the case. Because people deposited Anchor for 20% APY--quite number of people and article said about those 20% APY was not sustainable--you can find artcile like this Anchor Interest Rate, Can They Keep the 19.5% Interest Rate? @ March 14, 2022

Or reddit question like this - Explain like I'm 5: Where does the 20% interest on UST come from?

So if people realised this, they surely withdraw all the UST from there, right?

I think this could be the main reason:

The biggest reason that most people held TerraUSD was because of something called the Anchor Protocol. Think of Anchor as a savings account for your TerraUSD, but it pays you 20% interest — which is a really good deal for a savings account.

In past months, it made sense to simply park TerraUSD in an Anchor account and watch the 20% yield come in, especially because there’s not much you can actually use crypto for. Until as recently as last Saturday, 75% of all the TerraUSD in circulation was deposited in Anchor, according to Coindesk.

But in March this year, Anchor passed a resolution to replace the 20% rate with a variable rate

quoted from Why Did Luna (And The Rest Of Crypto) Crash This Week? @ May 14, 2022 by Richard Nieva, Aman Sethi

How Anchor can pay 20% interest rate?

"Anchor offers market yields of up to 20% on the year." That means Anchor must have enough funds to generate what people desposited here, right?

I don't know the details of thier process--yield interest rate require some time for example, deposit lockup period.

But I will just simplify it.

14 billions UST * 20% APY / 365 days =  about 7,671,232.87 UST/day.

Yield interest takes some time so I will calculate again.


At March 1, 2022, Anchor's deposted UST is about 8.2 billions--below chart.

Total deposit and borrow on Anchor protocol chart - screenshot from Anchor Protocol dashboard

8.258 billions UST * 20% APY / 365 days =  about 4,524,931.50 UST/day.

about 4,524,931.50 UST/day * 30 days = about 135,747,945.20 UST/month.

As you can see, Anchor must have daily income of more than 4.5 millions UST. But they don't have enough income so they try to change the 20% rate to variable rate. But it was way too late.

So you have to ask how Anchor can make that much UST? That means probably Luna Foundation just printed UST without any money(real process is bit more complicated though--minting the UST from burn Luna coin)--which all goes to the open market.

I think I can say that Anchor brankrupted. Or they just printed more UST.

About 10 billions of UST goes to the market for sell.

UST, a so-called algorithmic stablecoin, works with its sister token, LUNA, to maintain a price around $1 using a set of on-chain mint-and-burn mechanics. In theory, these mechanics are supposed to ensure $1 worth of UST can be used to mint $1 of LUNA – which serves as a sort of floating price shock absorber for UST volatility.

quoted from The LUNA and UST Crash Explained in 5 Charts @ May 11, 2022 By Sam Kessler, Sage D. Young

UST called stablecoin but it actually is just artificial stablecoin. So if nobody wants to buy UST, UST can be less than one dollar. As you can read from the quote, Luna will absorbed those difference. But do you think Luna can absorb that 10 billions of dollar? Answer is no. That's why they crashed, right?

Luna Foundation(??) must have more than 14 billions worth of dollars--that's what Anchor's had. But they just have 2 billions worth of BTC in LFG(Luna Foundation Guard) Reserve. You can see the chart below.

CoinDesk Research, Luna Foundation Guard, Blockchair - Luna Foundation Guard Reserve Balance Over Time chart and quoted from The LUNA and UST Crash Explained in 5 Charts @ May 11, 2022 By Sam Kessler, Sage D. Young

screenshot from the CoinDesk Research, Luna Foundation Guard, Blockchair - Luna Foundation Guard Reserve Balance Over Time chart and quoted from The LUNA and UST Crash Explained in 5 Charts @ May 11, 2022 By Sam Kessler, Sage D. Young

But they didn't have that much money. So they--Luna and UST were all brankrupted.



Where those 14 billions of UST coming from? And how Anchor can afford 20% interest rate to pay?

If you try to find out about this question, you will understand why this is Ponzi scheme and fraud.

You probably have other question like this: How this 3 to 10 billions of UST came from in first place? Which will lead to quite complicated matter because it involved Luna and UST and how it works. I don't think I can explain all here because article will became too long so I will talk about it later.

Or you can read it article like this:

 - Stablecoins, explained: Why the crash of Terra and Luna has investors on edge - CNN @ May 13, 2022
 - The LUNA and UST Crash Explained in 5 Charts @ May 11, 2022
 - Why Did Luna (And The Rest Of Crypto) Crash This Week? @ May 14, 2022
 - Anchor Interest Rate, Can They Keep the 19.5% Interest Rate? @ March 14, 2022



P.S. People in reddit still saying it was an attack. So I wrote post like this - How withdrew UST from Anchor can be an attack? Anchor and UST was like--bankrupted.

Hopefully, more people understand the problem.


Thursday, February 10, 2022

Safari wasn't competitive enough. Because not open platform. -Open source is the future.


I've seen this tweet:


 I don't know much about the issue because I don't use Safari. But what I don't understand is 'fix the problem' or 'solve the problem' wasn't the fundamental issue, I thought. For example, design flaw or missing function was not the bug, right?


So I wrote about in twitter and below writing is almost same as my tweet.

I don't know much about Safari, now. But what I know is nowadays without open platform, you won't be competitive enough.

I googled about market share and I was surprised because Safari does quite good--19.84% source from Firefox only 4.18%. Chrome 63.03%.
So I thought I was wrong about what I wrote.

Web browser market share wordwide by all platform. at February 10, 2022


But that's all platform which means smartphone's web browser marketshare included.

So desktop marketshare will show I wasn't wrong.

Web browser market share wordwide by desktop. at February 10, 2022


Safari 9.85% but Firefox also similar like 9.16%. And that's not end there because Edge 9.53% which Microsoft decided to become open source. And chrome wasn't exactly open source but chromium is. So can call open platform.

I didn't google about the Safari but I remember when I was using Safari in Windows several years ago. And I never heard after that.

And Chrome and Firefox all support multiple platform. But I don't think Safari does.


screenshot of 'Safari version history - Wikipedia' src:wikipedia at February 10, 2022


And when I try to make wallet for some cryptocurrency. Many were support web browser app which call the web browser extension or addon. So I can conviniently use cryptowallet.

Oh, sure, many crypto probably have iOS and android app.

But I don't think I have seen any web browser extension app for Safari. Mostly Chrome and Firefox. Sometimes, Edge, too.


So I'm quite sure that I can say Safari('s closed platform) can't catch up with open platform like Chrome, Firefox and even Microsoft's Edge.

Here is the what I wrote in the tweets:

You can read more about it--Open source is the future. I will talk more about it--later. @ February 7, 2020


Friday, February 7, 2020

Open source is the future. I will talk more about it--later.

I thought about writing this about a year(or less) ago. And I think I did write a few pieces about it but I wasn't able to find it--I have so many text file on my hard disk drive so I didn't have enough time to check out everything.
So I will write a piece first.

You can click here to what I talked about 'open source' in my twitter.

Long ago, Microsoft as evil empire or something.

Not so long ago--or a few or a decades ago, people called Microsoft as evil empire so when people mention about the MS(Microsoft), they wrote as 'M$' or something.
When I saw that 'M$', I thought that's how abbreviation works--or slang in English. At the time, I haven't learn English so I might slightly messed up my memories.

But time has changed.

screenshot @ 1:50p.m. February 7, 2020: Number of Linux distros on Microsoft Store
You can find number of Linux in Windows 10's Microsoft Store like photo above. One of the most famous open source project is Linux. And Windows 10 support it.

So I think I can say Windows 10 started to support Linux (kind of...) natively.

screenshot @ February 7, 2020: Windows Subsystem for Linux in Windows 10's Windows features.
You probably need update Windows 10 to see the Windows Subsystem for Linux from Windows features like photo above.

Microsoft shipped full Linux kernel about last May which I tweeted about it:

It was still development stage, I think.

And that's not all.

If you are using Android smartphone, you can go to find bunch of free Microsoft apps in Google's play store. Android is open source and Microsoft made a lots of apps for it.
And number of Microsoft's Windows application like calculator made it to the open source. is software development platform. And I think it is very famous website for the 'open source software project'.
And you can find so many github project from Microsoft--you can click here to see it yourself.

I just found Microsoft has open source project website

See. I am quite sure that I can say 'time has changed'.

* I will talk more about it later. I don't know when can I write more but hopefully soon.

Friday, June 28, 2019

Huawei doing just fine with so much pressure from the USA.

I wrote about this in another blog which I can't put link here because that's totally different blog.
But at least, I will summarize it.

Huawei leading the 5G markets.

Here is the news about Huawei leading the 5G markets:

the Chinese telecom equipment supplier managed to secure 50 commercial contracts worldwide making it the biggest 5G equipment supplier in the world.
Nokia and Ericsson take the second and third place with 30 and 18 contracts, respectively.
Huawei is dominating the market due to its 2160 5G SEP patents whereas Nokia holds 1516.
It appears that despite the US ban on Huawei's 5G equipment, the company managed to maintain its leadership worldwide.
quoted from news - Despite issues, Huawei leads the 5G market with 50 commercial contracts @ June 25, 2019

Huawei CEO Ren Zhengfei recently said that company's expected revenue will decrease about $30 billions. You can read news like this - Huawei says U.S. ban hurting more than expected, to wipe $30 billion off revenue - Reuters @ June 17, 2019
So if there has no 'Huawei ban', they probably had more 5G contracts. Worst situation but Huawei is doing just fine.

Huawei P30 series reaches 10 millions sales.

Many people and medias were saying that smartphone sales will be brutal because U.S. chip makers and OS(Operating System) software company can't sell their products to the Huawei.
I surely agree with that.

But some media reported completely wrong information like this - Huawei price shock? Where can I buy that $130 P30 Pro you mentioned? @ May 27, 2019
I agree that secondhand price will be go down because of Huawei ban. But who want to sell their 1,000 dollars smartphone for 130 dollars?

They think Trump is the God that Huawei ban can destroy a company--easily destroy sold products...or something. Or they think Chinese products are all rubbish that they can get it for free.. Or something.

Huawei shipped over 10 million units of P30 series in 85 days - #MWC19

this smartphone series has now exceeded global shipment of 10 million units in just 85 days.
quoted(include photo) from Huawei Central - Huawei shipped over 10 million units of P30 series in 85 days @ June 27, 2019 by Deng Li

This is news from GSMArena. just 85 days - that's two full months faster than the P20 phones. Also, it's a new 3-month sales record for Huawei phones.

And that's not all -
the Huawei P30 Pro received the "Best Smartphone" award from the European Hardware Awards. The SuperSpectrum and SuperZoom camera technologies were touted as major innovations by over 100 tech editors.

One more thing about smartwatch:
The company shipped 5 million units in the first three months of this year - according to an IDC report that's a growth of 282% year over year. Huawei is now a Top 3 smartwatch maker.
quoted from news - Huawei P30 series reaches 10 million sales in 85 days @ June 27, 2019

That SuperSpectrum is what I previously wrote about--the 'dark sight' - Huawei P30 Pro has not only super zoom. Dark sight, too. @ June 6, 2019
Huawei P30 Pro can take photo in the dark area so it probably far better than any other better low light camera like P20 series, Mate 20 series and Google Pixel 3 series.

Tuesday, June 18, 2019

Xiaomi Mi 8 selfie vertical video upload resolution problem-to youtube. Orientation problem.

I didn't really try to recording video with my smartphone before. And especially use with selfie camera.
But nowadays I'm thinking about recording video because it seems to me that not many people (in my country) trying to read article from the internet--especially like my blog--because I don't lure people.

Anyway, after record video with front camera, I think video quality wasn't bad. Actually it was quite nicer than I expected.

So I tried to uploaded to youtube but video resolution was reduced to 480p.
I think it has some problem with vertical video resolution, Mi 8 recorded vertical mode in slight different(or proper) way--like photo with portrait setting. 

but as you can see, video quality isn't good because it's jut 480p video.
So I googled about it and it looks like nowadays youtube will recognise 1080p video very well if uploaded video file is 1080p.

I uploaded it again(and again) with different filename--because if it's same filename, it became duplicate video. But it was same 480p video.

And I realised that video is vertical video so I googled about it--with keyword like this - 'youtube vertical video quality'.
Last year, youtube properly work with vertical video--without black bars.

Xiaomi Mi 8 portrait video is like photo's--based on orientation info.

And it seems to me that if it's 1080p vertical video, youtube properly work. So why my video wasn't uploaded it as 1080p video.
So it must be problem with my video file.

And I remembering some playback issue with PotPlayer which is video player in Windows 10. Last time, it did rotate whole screen to play this vertical--portrait video.

Screenshot of vertical-portrait video's media information in VLC player.

As you can see in the photo.
Video resolution is 1920x1080. If it's portrait video, it should be 1080x1920, right?
So how this can play as portrait mode?

You can see next highlight item in the photo. Orientation is 'Bottom right'. I don't' know what it refer to the 'Bottom right' is but I know this orientation thing when I was trying to editing the photos.
Sometime, this orientation things make mess when I am trying to editing it or uploading it to photo sharing websites.

So I had to use open source software Shotcut for just export to mp4 file. After that, I can upload to 1080p which you can see from below:

I'm not quite sure where should I report this issue. Xiaomi Mi 8's video shouldn't record like that--don't use orientation setting or something. Or youtube should properly recognise orientation setting in video files.

Or I didn't use properly like need some setting in portrait video mode (there has no other settings though) or something.

Thursday, June 6, 2019

Huawei P30 Pro has not only super zoom. Dark sight, too.

I heard about Huawei P30 Pro's super zoom capabilities. Because P30 Pro has periscope lens which can optically zoom in for 5x.
It isn't end there because it can do 50x zoom which isn't optical zoom though.

You can easily find article like this:

or you can see super zoom in action from youtube video:

And then suddenly the US president Trump and his administration added Huawei to the entity list which means any U.S company is not allow to do business with Huawei. More simple term is "Huawei ban".

So I didn't have time to know more about Huawei P30 and P30 Pro.

And I just found this youtube video:

The Huawei P30 Pro Is The Low Light Camera King And It's Not Close by ben's gadget reviews.

P30 Pro can take photo in the pitch black--dark sight.

I took screenshot from the video:
Screenshot of youtuber ben's gadget reviews' P30 Pro pitch black dark shot.
As you can see, it was very dark alley. And P30 Pro can take a photo like that.

Screenshot of youtuber ben's gadget reviews' P30 Pro pitch black dark shot.

Here is the comparison shot--P30 Pro vs iPhone XS vs Galaxy S10 vs V40.

Screenshot of youtuber ben's gadget reviews' P30 Pro pitch black dark shot.
Same comparison shot but different location-indoor pitch black shot.

As you can see, P30 Pro made whole new concept of nighttime photography--with just smartphone.
I would say P30 Pro blows competition--Google's night sight, out of the water.
And I'd like to name the P30 Pro's night mode as 'dark sight'.

Here is interesting comments that I'd like to share:
Screenshot of youtuber ben's gadget reviews' P30 Pro pitch black dark shot video's comments.
jim kuan commented:
If Apple were to do this, they will make a huge deal out of it.  They will have convention style announcement and give it names like "Quantum Retina Night" technology of the future.  And Huawei just puts it in their phones and says, "oh, by the way, we got a camera that can shoot in dark." 

Anyway, when I saw that video, I tweeted about it like this:

You probably need more evidence. So I will put some more articles.
Huawei's P30 Pro has the best low-light camera, better even than Google’s Pixel Night Sight, and it sets a new benchmark for night photography.
quoted from Huawei's P30 Pro raises the bar for low-light photography @ April 1, 2019 by Vlad Savov

Very low light: No contest

The P30 Pros ability to shoot in the dark is downright amazing. In fact, the darker it gets, the more stunning the results compared to any other smartphone out there.
quoted from Huawei P30 Pro vs Pixel 3 XL: The ultimate low-light camera comparison @ April 2, 2019

Below one is the good example. Author tried to do the blind test but he couldn't...
Huawei ruined our comparison

The initial idea behind this article was to take the best smartphones available on the market in terms of photographic capabilities, take pictures in dimly lit environments or at night, and then have you vote to choose the best shot. However, Huawei managed to ruin the comparison: P30 Pro in most scenes is unbeatable and too easily recognizable.
quoted from Huawei P30 Pro ruined our night camera blind test @ April 24, 2019 by Luca Zaninello

Huawei sets new standards in mobile photography with P20 Pro--and P30 Pro, too.

Many people think that Google Pixel 3 XL's night sight is game changer. But Huawei P20 Pro and Mate 20 Pro actually beat the Pixel 3 XL include night sight--which not many people know.

Here is the some of things you probably didn't know because people in your country don't use Chinese smartphone.

Marvelous! Huawei sets new standards in mobile photography with the Leica Triple Camera, and....

Overall, the P20 Pro offers the most comprehensive and flexible package, with the best image quality in terms of our comparison devices.....

The big advantage for the P20 Pro is its Leica Triple Camera, which blows the Mate 10 Pro and the competition out of the water.....

Huawei has set new standards for mobile photography with its Leica Triple Camera. The P20 Pro is the device against which all other smartphone cameras will now be compared.
quoted from Reviews - Huawei P20 Pro Smartphone Review @ April 20, 2018 by Daniel Schmidt

I don't really bother to checking out DXOmark score because DSLR cameras and lenses weren't that reliable source to get to know the DSLR camera and lens.
But smartphone was quite simpler than DSLR or mirrorless camera. Because photographer's diversity of photographing chances and styles with variety combination of DSLR camera and lenses makes hard to justify the DXOmark score.

When the Huawei P20 Pro was reviewed, there has no match to any other smartphone.
You can read more details in the review.

Conclusion: Game changer

We are used to every new smartphone camera generation being slightly better than the previous one, but looking at the images and test results from the P20 Pro, it seems Huawei has skipped one or two generations. The results are simply that good. The P20 Pro’s triple camera setup is the biggest innovation we have seen in mobile imaging for quite some time and is a real game changer.
quoted from Huawei P20 Pro camera review: Innovative technologies, outstanding results @ March 27, 2018 by Lars Rehm

You can find similar talking like this about people in your country don't use Huawei smartphone:
A majorly disappointing aspect of this entire test is just how unlikely it is for the US is ever to see a Huawei-made handset.
quoted from Pixel 3 Night Sight vs Mate 20 Pro Night Mode - 9to5Google @ December 3, 2018 by Damien Wilde
I will just quote some:
There isn't tons of detail but from what we had to work with initially, I think that Huawei seems to handle lighting a little better than the Pixel in my experience with both smartphones.....

Instantly with the Pixel and Night Sight, we see a greater level of detail, but it feels a little whitewashed overall.

As you can read this 'a little whitewashed overall', right?

The Pixel's eagerness to whiten up images in Night Sight is....

The Pixel tends to whiten up warmly lit scenes, which we feel does rob them of their ambience.... will handle incandescent lights better and preserve the vibe of the scene.
quoted from Night mode ON: Pixel 3 vs. Mate 20 Pro : Night Sight vs. Night mode @ November 23, 2018 by GSMArena team

You can read last part--"preserve the vibe of the scene".

Is this the reason why people trying to take photo of?
If you are familiar with computer, you will know the term wysiwyg--what you see is what you get. Whitening the scene wasn't that great way, right?

I'm not just making this up.
Here is the comment from Pixel 3 Night Sight vs Mate 20 Pro Night Mode - 9to5Google @ December 3, 2018

Screenshot of comments from Pixel 3 Night Sight vs Mate 20 Pro Night Mode - 9to5Google.

Skipper commented:

I use a Pixel 3, but one of its problems is photos look fake. Don't get me wrong, I love tinkering with instagram's filters, but come on, if you compare 3's photos with the 20pro, it's pretty obvious that 20pro is more realistic with 3 physical cameras capturing a "wider" aperture look, while Pixel's digital light enhancement is just that, "digitally enhanced", which mean "fake" look by tuning up highlights and shadows.

SF Media commented:

both are amazing..but the pixel is too bright for a night.

Anyway, Pixel 3's night sight probably improved a lot and Pixel 4 which wasn't come out yet, might be better.

But Huawei P30 Pro again made whole new concept of nighttime photography--with smartphone. And super-zoom, too.

Game changer phones which not many countries were available to buy. Because the U.S president Trump and his administration trying to destroying one private company--Huawei.

Monday, May 27, 2019

Huawei price shock? Where can I buy that $130 P30 Pro you mentioned?

Here is the article - Huawei Price Shock: Value Of Flagship $1150 P30 Pro Comes Crashing Down To $130 @ May 26, 2019
saying that it values $130. Because of Huawei ban.

On the same site, the Huawei P30 Pro, also in good condition, will now return just £100, less than $130. It has lost almost 90% of its value.

"Trade-in prices for the P20 Pro are now as low as £50," which quoted from U.K.'s Express newspaper--P20 Pro SHOCK as Huawei fans suffer most devastating news yet | @ May 25, 2019
Quoted from Huawei Price Shock: Value Of Flagship $1150 P30 Pro Comes Crashing Down To $130 @ May 26, 2019

This newspaper screenshot the trade-in values from MusicMagpie websites.

But as you can see from the photo, they were selling refurbished Huawei P20 Pro for £314.99 to £459.99.
So they can make £300 to £400 from cleaning the phone? Is this what people call it as "rip-off"?

Huawei price shock? Where can I buy that $130 P30 Pro or  £50 P20 Pro you mentioned?

If you can't see clearly, you can use this link--google photo link.

Trade-in company don't want to risk--because of Huawei ban. Sure, price will drop because of update issue.
But it doesn't mean secondhand price drop like £50. See above--in the photo. Even sell £350 but buy £50?
Huawei P30 Pro return just £100, less than $130??

Do some research--you don't even need to be in UK to find out--> Just google with "second hand p20 pro in uk".

If price drop like that, people will buy it form there and sell to other country--that's why a lot of people carry iPhone to sell other country--several years ago.

If I can buy P30 Pro for $130, I will surely buy it --3 or 5 of them. And P20 Pro for £50, I will go to buy 3 or 5 of them.
And if I can't sell it in my country(because almost nobody use Huawei phone), that's okay. Because I can give to all my family and friends.

* Many times, won't sell many Huawei smartphone--or Xiaomi smartphone. I know this because I did try to buy it from there. I think reason is not many people (in the USA), using Chinese smartphone. So I don't think it will impact rest of the world--I mean secondhand price of Huawei smartphone.

* Here is the list of link that I use in the photo:

Saturday, March 16, 2019

Can Raspberry Pi boot from USB flash drive? And about how to do it guide.

Simple answer is 'yes, it can' but read on....
Or skip to the "So I will write summary first:" below.
Or skip to the "Raspberry Pi 3 B+ support USB boot.  How about Pi Zero W? Or other Pi?" below.

Not everyone is beginner, I think.

When people looking for how to guide for installing the OS(operating system), they were probably beginner or very first time trying to use Raspberry Pi. If that's the case, step by step guide might be very good choice.

But even so, it is better to explain general concept, I think.

If someone already knew some computer stuff, he or she probably doesn't need that step by step guide. Because Raspberry Pi is computer that means it is same concept.
For example, someone is Windows user like me and some Windows user knew if computer--motherboard support USB booting, Windows user can simply go to the CMOS setting and do boot from the USB stick.
So I'm thinking Raspberry Pi is computer so it might support USB boot, too.

So I'd like to know whether Raspberry Pi support USB boot or not. Or I might have to do something to get USB boot.
That's what I want to know, right?

So I will write summary first:

BCM2837-based Raspberry Pis which were all the Pi 3 models include compute module 3 and Pi 2 Model B v1.2, support USB host and Ethernet boot.

So if you have any of models with BCM2837, you can follow any general install OS guide (and install to the USB flash memory stick) which you might already knew.

And if you have other models include Pi Zero and Zero W, you need single file on your micro sd card and then it will boot from USB memory stick. So you can boot from USB memory stick and also need micro sd card with single file which I will explain below.

thought about boot from SD and then USB.

I am currently using the multiboot via berryboot.

And sometimes, I felt berryboot wasn't enough what I am trying to do. So I am thinking about like that.
3 or 4 OS on SD card and then 1 or 2 OS from USB flash memory.

So I was googling about it like this:
how do i install raspbian on usb memory

And I clicked below guide:

And read this part:
Important information
This tutorial is out-dated and has been updated here: ....
So I did clicked link which is below guide:

I have a Linux machine but most of my data--Raspberry Pi image file and etc, was on Windows which is my main computer.
So I clicked Windows version tutorial--below link.

I appreciate the detail guides. But when I am trying go through this guide it made me very confusing.
See this "Step 2 – Install Raspbian to the micro sd card"
And then "Note: If you’re using a Raspberry Pi 3+, you don’t need to do step 2. Jump straight to step 3."

"Step 3 – Install Raspbian to the USB Flash Drive"
The process is exactly the same as step 2, but this time we choose the USB flash drive as.....

And here--"If you're using a Raspberry Pi 3 Model B+, you can skip step 4."

"Step 4 – Prepare the Raspberry Pi for boot from USB"

"Step 5 – Boot Raspbian from USB Flash Drive"

I realised that it is exactly same step as install Raspbian on micro sd card.

I have Raspberry Pi 3 B+ and Pi Zero W. So I already knew how to installing any OS on micro sd card.

As you can see, it took very long time to figure out.
Unfortunately, I clicked very old guide--May 2013. That probably is the reason though.

Raspberry Pi 3 B+ support USB boot. How about Pi Zero W? Or other Pi?

I am thinking newer Pi can support boot from USB memory stick but how about Raspberry Pi Zero W which I also have.

So I googling about it and found this:

This question already reveal how to do the booting from USB stick.

Quoted from the question.
The older Raspberry Pi's (Pi 1, Pi 2 and Pi Zero) couldn't boot from a USB-device, but the Raspberry Pi 3 has support for it. The Pi and Pi 2 have semi-support for it (using an SD-card with a single bootfile).

So if I wanted to boot from USB stick in Pi 1 and 2, I can place single bootfile--which I don't know it yet.

And other people answered that Pi Zero W use older chip like Pi 1 and 2.

And then I found someone wrote about that single bootfile--bootcode.bin.
And pointed to the source:
Special bootcode.bin-only boot mode section in Raspberry Pi boot modes - raspberrypi/documentation
Quoted from above link:
USB host and Ethernet boot can be performed by BCM2837-based Raspberry Pis (these are all Pi 3 models, and some Pi 2Bs). In addition, all Raspberry Pi models can use a new bootcode.bin-only method to enable USB host and Ethernet booting.

Just format an SD card as FAT32 and copy on the latest bootcode.bin.

This is useful for the Raspberry Pi 1, 2, and Zero models, which are based on the BCM2835 and BCM2836 devices, and in situations where a Pi 3 fails to boot (the latest bootcode.bin includes additional bugfixes for the Pi 3, compared to the boot code burned into the BCM2837).

If you have a problem with a mass storage device still not working even with this bootcode.bin, then please add a new file 'timeout' to the SD card. This should extend the time it waits for the mass storage device to initialise to six seconds.

I'm not 100% for sure yet. But if Raspberry Pi use BCM2837, USB host and Ethernet boot will support.

And I found all the Raspberry Pi specifications from Raspberry Pi - Wikipedia.
Screenshot of Wikipedia's Raspberry Pi Specifications section.
And as you can see, Pi 2 Model B v1.2 uses BCM2837. And all the Pi 3--3 Model A+, 3 Model B, B+ and Compute Model 3, lite, 3+.

So if you have Pi 2 Model B with v1.2, Pi 3 series and Compute Model 3 series, you can just install any OS on USB stick and remove micro SD card.

If you have other version include Pi Zero W, you can format the micro SD card and copy the bootcode.bin file.

Yes, I haven't tried it yet. But I think those are from the Raspberry Pi's official repository.
So I'm sure it will work.

Kali and Raspbian booted from USB flash drive.

I probably have to get more information about it so I just found this:
quoted from above link:
HawaiianPi wrote:
The Pi3 will check for a boot SD card first, before booting from a USB device. If no boot SD card is found in 5 seconds, then it looks for a boot USB device.

I think this is quite similar process as USB boot in PC--desktop and laptop computer.

When I read from above link, someone said some USB disk won't work. And I wasn't sure about it--If it's FAT32, why it shouldn't be.

But first I tried with quite old 8GB USB stick, it didn't work--Pi 3 B+ without micro SD card and Pi Zero W with single file on micro SD card.
So I thought I need to do something.

And I realised this could be compatibility issue. So I put my kind of new memory card read which can read SDXC format card, too.


As you can see that micro sd card slot is empty.
Kali lite booted from USB Flash memory stick in Raspberry Pi 3 B+.
That USB memory stick doesn't work with USB boot--I tried like 2+ os and also with Pi Zero W.

This time, I tried same USB memory card reader with Pi Zero W. And it worked well.
And I had to put single file in micro sd card.
Raspbian stretch booted from USB Flash memory stick in Raspberry Pi Zero W.

If you'd like to connect more than two USB stick, portable hard disk or SSD, things became quite complicated. Because Raspberry Pi doesn't know which USB drive to boot from.

So you have to search more about it.

I hope you did learn about the basic concept or process of USB boot in Raspberry Pi.

Friday, March 15, 2019

Adafruit's Portable 5 inch Monitor with HDMI DIY looked interesting. But in reality....

I've seen this video: Portable HDMI Display for Raspberry Pi - YouTube

And I thought it looks very nice and quite useful because it isn't only for the Raspberry Pi--I can use as my DSLR monitor or game console monitor as well--I have a Nintendo NES classic edition which is kind of portable console.
So I'd like to do this....

It's expensive than I expected.

But when I saw inside of it, it shouldn't be easy to do.
Building the portable monitor won't be easy, for sure--I haven't done soldering before. But it requires a lot of parts to buy, too.

And if I do this, I might learn a lot of things about Adafruit, for sure.

So I visited building guide wep page.
Overview | Portable 5in Monitor with HDMI | Adafruit Learning System

And I realised I don't only spend a lot of time, I need a lot of money to building it, too.

  • 5.0" 800x480 TFT Display $29.95
  • TFP401 HDMI Breakout $24.95
  • FPC Extension Board $4.50
  • Powerboost 1000C $19.95
  • 2500mAh Battery $14.95
  • Slide Switch $0.95
  • Tripod Screw Insert $1.50
  • Total: $96.75

I thought this is too expensive for me. I need other things like print 3D case and lots of tools to do this.

So when I go through their guide, I saw that it can powering up the screen through USB.
That means, I can simply use my smartphone powerbank.
So no need to buy Powerboost 1000C and 2500mAh Battery.
And I don't have 3D printer so I don't need slide switch and tripod screw insert, too.

So I need three parts--5 inch display, TFP401 HDMI breakout, FPC extension board.
So total $59.4.

Cheaper or even better alternative--Aliexpress.

That means I don't need to do this.
Because I can simply buy from cheap Chinese store in Aliexpress, like this:
This is screenshot of 5 inch capacitive lcd display from Livetime Store in Aliexpress.
5 inch Raspberry Pi 3 Model B+ Touch Screen 800*480 Capacitive LCD Display + HDMI Cable + USB Cable + CD for Raspberry Pi 3-in Demo Board Accessories on

This is 5 inch capacitive touch display. And it costs $38--include free international shipping.
This model was different driver board design than 5 inch resistive display so I couldn't find case for this model.
5 inch resistive display case costs $6 to $10 in Aliexpress.
I can buy 5 inch display with case for about $48.

So it's much cheaper and better(include touch panel) than Adafruit's.
I know this because I just ordered one from there. So I search the a lot of similar--5 inch lcd.

If I wanted to learn about Adafruit, I probably can invest that much time and money.
But now I'd like to more focus on Raspberry Pi--and programming.

So I will buy 5 inch capacitive touch display.

You can also buy other 5 inch screen from Aliexpress like this:

This is the screenshot of '5 inch lcd hdmi' search result in Aliexpress.
Buy 5 inch lcd hdmi and get free shipping on

This is the screenshot of '5 inch screen' search result in Aliexpress.
Buy 5 inch display and get free shipping on

When you are searching the lcd screen, it doesn't show up many items. But you can find store that specialize in Raspberry Pi or SBC(single board computer). So you probably have to check Raspberry Pi store one by one.

It looks hard to build but maybe not that much.

At first, I don't think it's easy thing to do. When I saw this link:
On/Off Switch | Portable 5in Monitor with HDMI | Adafruit Learning System
It doesn't seem to easy, does it?
But if you are thinking about portable project, I think it's worth the effort.

I saw the next page. And if I learn about soldering, I think I can do this.
TFP401 Driver | Portable 5in Monitor with HDMI | Adafruit Learning System

And next,
Display | Portable 5in Monitor with HDMI | Adafruit Learning System
This part need just connect and position the cable. After that, screen is working.

Next part is mounting to the case.

Overall, if I learn and practicing soldering, it shouldn't be so hard.

But I still don't have a 3D printer and I don't like spend that much money.
So I will buy from Aliexpress.

Many of web store like adafruit, elements14, sparkfun, pimoroni were probably based on USA or UK so shipping and currency is too expensive to my country--Korea.
And same kind of store in Korea was all imported from those countries so things were much more expensive.

That's why Aliexpress is the best choice--for me. And probably to you, too.

Monday, December 17, 2018

How the sixty dollar console-Nintendo classic mini, costing an arm and a leg?

Summary – Sad story of a sixty dollar console costing an arm and a leg.
quoted from one of Amazon user's Nintendo NES Classic Edition Console review:

I also found similar one from customer Q&A sections @ #Amazon's Super NES Classic item page
Q: Will we ever have a chance to buy this?...
A: willing to pay but when you make it impossible to get except rip-off-bay it makes it meaningless that....

Simply put - Nintendo didn't make enough products and they just kept trying to shutdown the productions because they wanted sell their other main line product like Nintendo Switch.

Here is evidence of what I said was probably true:
Despite the positive reception, journalists were confused about Nintendo's decision to discontinue the unit as announced in April 2017. Nintendo did not say at launch that the system was meant to be only a limited run, and its...
quoted from Reception section of NES Classic Edition - Wikipedia

Their products are selling so well but they were simply stop producing the product. Does it make sense to you?

NES Classic Edition

Nintendo NES Classic immediately sold out

The NES Classic immediately sold out when it was first released in November 2016, with resellers charging hundreds of dollars for the popular product.
quoted from Nintendo's NES Classic and SNES Classic are going out of production - The Verge

more details from Scalping and bootlegs section of NES Classic Edition - Wikipedia
This, coupled with the extremely high demand, prompted internet scalpers to buy as many as they could, so they could resell them with extreme price markups. In the US, prices were commonly set between $200 and $500, compared to its launch price of $59.99.

Sunday, June 17, 2018

answer--not physically destroy hdd, for erase data from a hard disk so no one can ever recover it.

Thinking about selling used hard drives.

Recently I bought external 2.5" hard disk drive because my external 2.5" hard drivers have low on free space. Copied all the data to new hard drive from old hard drives.
Now I have number of hard drivers--external 2.5" 500GB, 750GB and a few desktop PC 3.5" hard disks that no use. So I'm thinking about to sell it.

Before I'm selling, I needed to clean up the hard disk so no one can recover my personal data. I don't much have important data though--I have a lot of piece of writings and ideas. But I don't think people will understand what those a pieces of writing is for.
I know this because some of those ideas, I already wrote in my twitter or blogs but no one seems to understand what I am saying. So I don't much care about those.
But I have been learning photography so I have tons of photos which I'd like to erase it.

So I did googling and came across this--in Quora:
How do I erase data from a hard disk so no one can ever recover it? 

Why would you like to physically destroy hard disk which you spend a lot of money for?

Quite surprise to see so many answered with physically destroy the hard drive.

I thought -
Nowadays, everyone is sooo rich that everyone suggest to physically drilling, shredding the hard disk.
I'm not rich so I had to completely erase the data before selling.

I know the simple solution without physically destroying it.

I know how software works--because I was a programmer. So I know very easy and simple way. Download some software--bigger size will be better, useless documents or anything from the internet or your not important things like Netflix movie files. And delete all your data. And then copy the downloaded software, documents and all. And kept copy it(same files over and over--make folder to more easier--Windows will make new name for it like below screenshot) until hard disk became zero-ish byte of free space.
screenshot: overwrite files for make unrecoverable

So when the recovery software or professional try to store data from my hard drive, they will only recover those useless data.
It's THAT simple to permanently erase data.
Yes, it takes time. But it perfectly works.

Yes, someone answered what I suggested--overwrite data to remove personal data.
And someone saying that forensic analyse(or something) still can find a bit of information from there. Sure. That might be true.

That's why my solution makes more sense.

Because my personal data was already replaced by thousands, thousands and thousands of files.
That means forensic analyse take more, more and more time to figure out which bit of information connected to the which part of information. It's like thousands, thousands and thousands of jigsaw puzzles to figure out.
And it will be almost impossible because a lot of pieces were missing.

Loren Forslund answered very interesting one and I think it's very good method, too:
My method is using Ubuntu disks utility to break all partitions down and formatting the drive into one “FAT” partition. Now make 2 equal partitions and format them in EXT4 writing over the drive. Now break these partitions back to one NTFS partition over writing the disk. I’m sure if you had one million dollars worth of DOD equipment and 3 months of time you may get a scrap of something, but I doubt anything useful.

People watched way too much TV shows--CSI kind of TV shows.

Especially this part:
I'm sure if you had one million dollars worth of DOD equipment and 3 months of time you may get a scrap of something, but I doubt anything useful.
 - People were watched way too much TV shows
 - and they were way too much talk about this theoretical ideas.

Let's talk about reality.
I told you that I bought a external 2.5" hard disk which has 4TB space--actual size is 3.63TB.
So I put all my old data to this new hard disk..
screenshot: my external hard disk drive's files and folders

Last time, I had a lot of software and documents from the internet. But when I started taking photos, I had to delete those files because nowadays DSLR or mirrorless camera need bigger space to backup.
And other reason is I can always go online to get those software again.  So I don't need to kept in my hard drive.

So in my case, 50% of files(153,598 / 2 = 76,799 files) were probably personal data. But each photo was like 7 to 24 mega bytes only. I have software, downloaded documents, audiobook from Librivox and games and those were far more bigger size than photos.

So even if I have 50 to 70% of files were personal data(because photos I took), 40 to 80% of space were filled with not personal data. That means 40 to 80% of 0.98 tera byte.

That means if forensic analyse find a bit of information, it will quite likely not my personal data. For example, 70% of space were not personal data means:
other not important things - 1,003.52 giga byte * 70% = 702.464 giga byte
my personal data - 1,003.52 giga byte * 30% = 301.056 giga byte
Because my personal data was only 30% chance to picked up by forensic analyse.

And there has more. I have thousands of photos but do you think all of my photos were all very important photos--which I probably use it in my blog.
Photography is my hobby so technically it wasn't very important data.

Even if so, reality is this:
How many professional photographers really use all of their photos they took, do you think?

And how many people do you think they use their hard drive only for their important data?
Even if that's the case, why do they need 1 to 4 tera bytes of hard disk?

I have important documents but most of my documents(which I kept it in text file format--smaller than Word file format.) takes only a few kilo byte.
So I'm sure that a few giga bytes of hard disk should be enough for their personal--important data.

Reality of un-delete kind of software.

How I know this? Because about 10 or 15 years ago, I tried to recover my important data from un-delete kind of software with no success.
I can see the files with so many other files. But I can't recover it because it was already half destroyed--some new files already overwritten some part of those files.

You've known this, too. Good example is 'corrupted file'. Did you recover that corrupted file?

Reality is this:
Even if that forensic analyse find a bit of byte, what can you do with that part of byte?

It was 10 or 15 years ago experience so I have to check. And found this:
Recovering Deleted Files After Formatting: Is it Possible? | Deleted File RecoveryThere are many debates regarding the possibilities of recovering deleted files among computer scientists. All evidence points to the fact that in order to recover files deleted from recycle bin, or any other part of the operating system, they must not have been written over.

In order to recover a deleted file every sector that included data for that file must be in it’s original condition. Overwriting any part of this file with new data will cause corruption.

As you can see, this professional(??) data recovery company saying things were far different than what many people answered in Quora.
Professional data recovery company saying that they can't recover if it's already written over.
But many people in Quora saying that you can recover it--because you can find a piece of information with forensic analyse(or something). So you must do physically destroy hard drive--drilling, shredding, burning and among other physical way.

See the difference.

Even if you recover the part of file, you probably can't read--because of corrupted. But what many people in Quora saying is it can read--recover it.
* If you seen CSI kind of TV show, they can always recover it, don't they?
Yes, you can recover the random data. But do you think that random data is worth a million dollars with spent a few months or a year of work?

That's why I completely agree with what Loren Forslund said:
I'm sure if you had one million dollars worth of DOD equipment and 3 months of time you may get a scrap of something, but I doubt anything useful.

Reality is extremely different than what people were saying in internet, unfortunately.
This is how people kept getting more wrong ideas.

P.S. I found permanent file delete software:
They also explain same thing--overwrite to make unrecoverable.