Dorchester — Nov 11th 2014

We started the evening with a discussion on Yosemite. Opening the discussion, John suggested that from the various comments he had read it would seem best to stick with Mavericks for the time being. But the eight or so members present who had upgraded were quite happy with Yosemite; Graham had got over his early WiFi problems by switching from Automatic location to a manual setting. David and Drew had their Computers showing up in the shared list in the Finder multiple times which David understands is a know problem. Euan reported that very occasionally text entry slowed to a crawl. He solved this with a Safe Boot. John raised the question of loss of Templates when emailing from iPhoto. Whilst on David’s computer the Mail icon was dimmed, Graham had the full options, templates included. John could then not even open iPhoto on his computer only too discover that it was in the process of automatic upgrade. We will follow up at the next meeting.

David gave his short talk on Bitcoin (BTC) - worth that day £234 - the smallest unit being a Satoshi = 0.00000001 BTC. His interest had been aroused by the wider question “what is money and where does it come from”. Although not promoting the use of Bitcoin he could see the advantages of a system which allowed very rapid currency exchange across the World with no middlemen taking fees en route. The Network p2p technology requires no central service provider which will almost certainly have a big effect on new services being developed. David showed the simple IOS app enabling the use of Bitcoin but admitted that he lost his nerve trying to purchase any Bitcoin. The Bitcoin network is maintained by “miners”, anyone can become a miner. “Miners” verify all transactions and group into bundles called Blocks linked together in a chain hence the term Block Chain. Completing a block requires finding a Cryptographic Hash Function that meets certain criteria. Achieving that is rewarded with 25 BTCs. The complexity of the criteria is changed every 2106 blocks to keep a flow of approximately 150 new Bitcoins per hour. In 2040 the reward will drop to zero, by then there will be 21 million BTCs in circulation. David explained the basic idea behind a hash function, an algorithm that maps data of arbitrary length to data of a fixed length. The mining technology has become very sophisticated, and suitable equipment is readily available even from Amazon along with open source software for anyone with Terminal skills.

The evening ended with a 25 minutes edited version of Apple’s presentation of the Apple Watch which had many present disappointed that it would not be available for Christmas!

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