Understanding Bitcoin

Bitcoin: Is a cash system where the ledger with transactions is hold by a Peer-to-Peer public network, where anybody can check transactions.

In order to validate transactions miners have to do some work - solve some mathematical problems, and hence use some power and resources. The more people participating the more difficult the mathematical problems and the higher the security, as it requires huge amounts of processing power.
It becomes unprofitable for one individual to spend that much money on the hardware and power need it to run it vs the value gained.

Miners assemble all new transactions appearing into large bundles called blocks, which collectively constitute an authoritative record of all transactions ever made, the blockchain.

In order to make sure there is only one blockchain blocks are really hard to produce.
So instead of just being able to make blocks at will, miners have to produce a cryptographic hash of the block that meets certain criteria, and the only way to find one is to try computing many of them until you get lucky and find one that works. This process is referred to as hashing. The miner that successfully creates a block is rewarded with some freshly created bitcoins.

Every few days, the difficulty of the criteria for the hash is adjusted based on how frequently blocks are appearing, so more competition between miners equals more work needed to find a block. This network difficulty, so called because it is the same for all miners, can be quantified by a number.

Mining pools: by sharing their processing power, miners can find blocks much faster. Pool users earn shares by submitting valid proofs of work, and are then rewarded according to the amount of work they contributed to solving a block.

Resources:
Bitcoin core: https://bitcoin.org
The blockchain: https://blockchain.info/
To find bitcoin ATMs around the world: https://coinatmradar.com/

Best Bitcoin Exchange: https://www.binance.com/en

https://bitcoin.org/en/full-node#what-is-a-full-node

An episode on the inside man where Morgan Spurlock buys bitcoins and tries to live one week by it  : https://vid.me/gjbm/morgan-makes-cents-out-of-bitcoin

A documentary released in 2014 The Rise and Rise of Bitcoin

How is the bitcoin fee calculated ?

The value of the fee its not related to value of transferred bitcoins but by the size of the transaction in bytes.
This is calculated by the number of in transaction for the wallet multiplied by something like 180 plus the number of out transactions for the wallet multiplied by something  like 34. So getting bitcoins paid adds more to the fee then paying with bitcoins.
Then the bytes values of the transaction get multiplied by a value called satoshis that its network dependent : how many transactions are happening and what fees people use.
Most apps have some default values where they will use a value so that you transaction will get into the next n-th block based on some settings you input or uses some default values.
You can check satoshisvalue here : https://bitcoinfees.21.co/

How much profit can you make mining ?
(Your power / network hash power)* Coins generated per day * Coin price
Say you have 1 THash miner
1.03.2018 for Bitcoin:
(1/23.500.000)*1800*11.000 $ =~ 0.85$ / day

Minimum bitcoin transation is : 5460 satoshi or 0,05460 mBTC.
This is the same amount as the minimum fee recommended.
1 BTC  = 1,000,000,00 satoshi

Why is there a minimum limit of transaction in bitcoin ?
This limit is not forced by the protocol but by a consensus between both bitcoin clients as well as miners in an effort to fight transaction spam


Altcoins
Altcoins are the alternative cryptocurrencies launched after the success of Bitcoin, as peer-to-peer digital currencies, that offer modifications in areas like transaction speed, privacy, proof-of-stake, DNS resolution and more,  in an attempt to imitate that success.

How to solo mine bitcoin with vga

Get BFGminer 4.10.6 ( this one works for sure, i'm not sure exactly in what version they removed some option).
Download link here: http://bfgminer.org/files/4.10.6/

Get bitcoin core install and wait to download the blockchain - requires ~190GB of storage space [on 14.07.2018].
When you install the core chose to save the blockchain in other location then by default on C, for easier access. Put it in D:\Bitcoin if you have another partition or in C:\Bitcoin.
There you will have your configuration file: bitcoin.conf.
Note that depending on you internet connection it might take couple of days to fully download and sync to the network.
You cannot mine until the sync is completed.
Download link here: https://bitcoin.org/en/download

Now go and edit the bitcoin.conf file. If it does not exist just create one with notepad.

server=1
rpcuser=whaterver-user-you-like
rpcpassword=any-password
rpcport=8332
rpcallowip=127.0.0.1
disablewallet=1

Save and restart the bitcoin app.

Go to the folder where you unrared your bfgminer.
Create a mine.bat file to save the command so you don't have to type it every time you run it.

bfgminer -S opencl:auto -o http://127.0.0.1:8332 -u whaterver-user-you-like -p any-password --set-device intensity=9 --coinbase-addr 18Mzayw6yHve2zn1ZQkxKYnM9TcvfEF7Y2
pause

Replace the username and password with the ones you set in bitcoin core.
Go to https://www.blockchain.com/wallet and create a bitcoin wallet.
Replace the --conbase-addr with your new created wallet.
To get the address press the receive bitcoins button and you will get your address.

Run the file and I wish you good luck.
If you are lucky and win the bitcoin lottery don't forget to show your appreciation :)
My bitcoin address is: 18Mzayw6yHve2zn1ZQkxKYnM9TcvfEF7Y2

How to buy from china electronics cheap online

• Aliexpress - cheapest, only card payment 
• Gearbest -  best for buying phones, camera and laptops and accesories as well, also offers Paypal payments 
• Banggood - a bit more expensive but offers Paypal payments and has good customer service

Standard shipping takes from 2 weeks to 2 months.

When buying more expensive stuff it is worth paying for a tracking number.
For cheap 1-5$ products tracking cost its almost as much as the product.

On aliexpress you can get international tracking even with the no cost shipping method.

Nikon Coolpix P900 full spectrum / infrared camera modification tutorial

You can see in the video above how to remove the filter inside the camera for increased IR spotting.
This is the camera with an external IR filter :

K&F CONCEPT DIGITAL IR 720 67mm JAPAN OPTICS

COOLPIX P900

Coolpix 900 with IR Filter

Here are pictures taken with the camera :

Auto mode - no ir filter 

Auto mode - external ir filter 720nm

Enhanced monochrome - no IR filter

Enhanced monochrome - external IR filter 720nm

Ir filter 720nm cuts the red colors so its not the same as the original ir filter in the camera.

Monocrome mode with inside camera filter

Monocrome mode with inside camera filter removed

Apache mod_rewrite module tutorial

<IfModule mod_rewrite.c>
RewriteEngine On # Turn on the rewriting engine

</IfModule>

Rewrite rules can be preceded by one or more rewrite conditions.
Eg :

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /wordpress/index.php [L]

. (any character)
* (zero of more of the preceding)
+ (one or more of the preceding)
{} (minimum to maximum quantifier)
? (ungreedy modifier)
! (at start of string means "negative pattern")
^ (start of string, or "negative" if at the start of a range)
$ (end of string)
[] (match any of contents)
- (range if used between square brackets)
() (group, backreferenced group)
| (alternative, or)
\ (the escape character itself)

Flags :

C (chained with next rule)
CO=cookie (set specified cookie)
E=var:value (set environment variable var to value)
F (forbidden - sends a 403 header to the user)
G (gone - no longer exists)
H=handler (set handler)
L (last - stop processing rules)
N (next - continue processing rules)
NC (case insensitive)
NE (do not escape special URL characters in output)
NS (ignore this rule if the request is a subrequest)
P (proxy - i.e., apache should grab the remote content specified in the substitution section and return it)
PT (pass through - use when processing URLs with additional handlers, e.g., mod_alias)
R (temporary redirect to new URL)
R=301 (permanent redirect to new URL)
QSA (append query string from request to substituted URL)
S=x (skip next x rules)
T=mime-type (force specified mime type)

To redirect all requests missing "www" (yes www):

RewriteCond %{HTTP_HOST} ^domain\.com [NC]
RewriteRule ^(.*)$ http://www.domain.com/$1 [L,R=301]

Change rdp default port

If you have many computers at home or on a network and you have to connect to them remotelly using RDP you will have to change the default port and set a different one on every computer so you can then set the port forwarding rules on your wan router.

To change the default port you have to edit the registry.
Open regedit and navigate to :
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Terminal Server\WinStations\RDP-Tcp\PortNumber

Change the port for ex to 3390 , 3391 etc and then set the port forward rules mapping the port to a fixed ip. You can either set the computers with fixed ip or map them in the dhcp server with ip & mac binding or Reserved IP Address.

You can use check open port to check if your port forwarding is working properlly and the rpd service is listening to the specified port.

Google doodle halloween game 2016 highscore

No user name in task manager windows xp

To solve this open services : services.msc or in control panel.
Find Terminal Services and activate it and set it to Automatic.


Enjoy!

The trust relationship between this workstation and the primary domain failed

You can get this message if you restore a virtual machine, or have a raid problem and restore a raid 1 mirror from a slightly older hdd. I got and offline member for two weeks without noticing and then the second hdd when bad so i could not boot anymore.
Reactivated the offline member and changed the bad hdd rebuild the raid and then you get the error message while trying to access the domain.

Also got this but making an image of a pc in the domain and restored it a few month later to a new pc, then could not add it to domain.

You can try to remove it from domain and add it back and it should work.
Or (you need at leas Power shell 3.0 or upgrade to it if not) then run:
Reset-ComputerMachinePassword

Add user from cmd with admin writes and change password for admin account

To add a new user open cmd with administrator writes :

net user Username /add password

The user is a limited user. To give administrator writes :

 net localgroup administrators Username /add

To delete a username :

net user Username /del

To change the password of a user if you cannot access any windows account.
Boot from a usb and access the windows partition.
Go to C:\Windows\System32\
rename sethc.exe to sethc_.exe
copy cmd.exe and rename it to sethc.exe 

Boot to windows, when at login screen pres SHIFT key 5 times, and instead of the sticky keys message you get a cmd with admin writes.

Next change password with :

net user Administrator 1234 

Windows could not complete the installation

While installing windows at the end of the installation you get an error message and remains stuck in a loop.

Press SHIFT+F10 to open a cmd
cd %windir%\system32\oobe\
msoobe.exe

and then press ok to the error message and restart.

Intel Raid error occurred (0) offline member status failed

On Intel® Matrix Storage raid  you can get the errors :

error occurred (0)  - the controller has encountered read/write errors (the hdd has bad sectors) and should be replaced
 offline member - for some reason the hdd is offline and not active in the raid so the hdd is unused, you can get with this one in raid 1 with mirror as you will still be able to boot.

If you get an offline member and don't do anything and then you get an error occurred (0) as i got on a Supermicro X7DB3 server you will not be able to boot in os anymore.

How to fix it ?
Remove the error occurred(0) hdd - you can try by removing one by one restart and check raid members hdd status, then access the raid utility by pressing CTRL+I
and you will be asked to reactive the offline member.

Next buy a new hdd to change the error occurred(0) hdd and it will rebuild the raid back, you can still boot to windows just with one hdd until you get a new one.

Error Occurred(0) Degraded

RAID Rebuild

Offline Member Error Occurred(0) Failed

To see the status of the raid rebuild install :  Intel® Matrix Storage Manager.
You can get it from here :
https://downloadcenter.intel.com/search?keyword=Intel%C2%AE+Matrix+Storage+Manager

Intel® Matrix Storage Manager rebuilding

0x0000007b Blue Screen - no storage device found

0x0000007b Blue Screen

This means that windows cannot access the storage device.

Usually you have to go to bios and change sata from ahci to ide if this comes after windows installation.

If it appears while installing windows you have to provide storage drivers by pressing F6  

How to compress pictures

You need to get :  Microsoft Office Picture Manager. You can get it for free by downloading :
 Download SharePoint Designer 2007  - chose custom install and then select only “Picture Manger”

Next you have to select how much to compress depending on what usage you have for the picture in mind.

Add date and time to photos or timestamp them

Download and install : FastStone Image Viewer. It is a freeware program.
http://www.faststone.org/FSViewerDetail.htm

Next open the program and select Tools - Batch Convert Selected Images or F3

Next check the  Use Advanced Options and Select the Advanced Options button that appeared.
Select the Text tab - Insert button/dropdown menu - Date Time

You can customize position and font of the text by the red marked buttons.
Next select an output folder and press convert.

Disable yahoo news :

Open Yahoo Mail app
Drag from left margin to open the side menu, scroll down to Settings
 In the General section you have Notifications
First line should be News notifications settings - move the Enable notifications to off.