Computer Handyman

 The Visa card processing system handles about 1,700 transactions per second. The Bitcoin blockchain can handle about 4.6 transactions per second.  Other blockchains, such as the Ethereum, may be faster but they still cannot approach Visa’s speed.  Three components of blockchain play off against each other when you try to increase the speed of blockchains.   These elements are decentralization (how many computers maintain records), scalability (how fast each transaction can be processed), and security (how long it takes to verify a transaction).   Usually, to attempt to speed up a blockchain by changing how one of these elements works will adversely affect one or both of the others.   A block in a blockchain contains a number of transactions.   Each transaction records the buyer, the seller, the amount, etc.   The initial Bitcoin block size was 1 MB, which could hold about 2,759 transactions.   One way to increase the speed would be to ma...

I have had two brushes with Vietnam during my life: one was serving in the Army artillery in Vietnam during the war, the second was overseeing databases of Vietnamese who wanted to go to the United States after the war.  When I was in Vietnam from 1969 to 1970, I had very little interaction with the Vietnamese. I was in a heavy artillery battery that supported American Army soldiers on the ground.   Most of the time we were stationed at firebases in the middle of nowhere, with no Vietnamese around.   A few times we had Vietnamese units on the same firebase, but we did not interact.   They supported Vietnamese units and we supported American units.   We were in northern South Vietnam, which the Army called I Corps.   Occasionally I would ride into town with supply trucks; so, I occasionally saw Hue and Quang Tri. At Firebase Barbara, on a lonely mountaintop not too far south of Khe Sanh on the Laotian border, all of our resupply was done by helicopter. ...

Cybercurrencies are here to stay.  Maybe Bitcoin is too, but not at the levels it currently holds.  Tulips are still here, but the tulip mania of the 1630s has passed.  Bitcoin was originally intended to be a medium of exchange that would be insulated from almost all external control.  This anonymity made it an excellent means of exchange for illegal activities, most recently illustrated by the fact that most of the ransomware attacks on private data have demanded payment in Bitcoin.  Bitcoin transactions are recorded by blockchain, which is like an old accounting ledger.   It contains every Bitcoin transaction, although looking at blockchain from the outside, you can tell that a transaction is verified, but you cannot tell who the parties were or how much Bitcoin was involved.   As one of the parties to the transaction, however, you can pull out the specific information.   So, if Elon Musk for example says you never paid him for your Tesla, y...

I am trying to install GoogleAdSense on my Computer Handyman website , but all I get is a blank, blue space where the ad should go. I guess the problem has something to do with the way my CSS is set up, but AdSense says it may take 48 hours to start working properly. So, I will give it some more time.

  GoDaddy’s ftp connection for their websites does not work like most ftp connections do.   For most ftp connections, the address starts with ftp, as in ftp.website.com , but GoDaddy wants you to leave off the ftp prefix.   I could not connect by ftp to my GoDaddy website , it-handy.com .   I tried for a long time to figure out what was wrong – my password, my user id, etc.   Nothing was wrong except the address of the ftp connection.