Re: You are dead right about replacing cores

Post #33,118 by dmarker2 3/22/02 4:34:08 AM Reply	Re: You are dead right about replacing cores We field CEs never did to my knowledge. I just couldn't resist obtaining a pair of the tweezers from our tool store just to show people what they looked like. I have no idea why the tool store even had them. Being on night shift we had the power to apply for & obtain practically any tool in the inventory - we had by far the best toolkits of the entire field force. Funny story re cores - I remember a guy getting an award for about $US100,000 (a massive amount in the mid 1960s) for solving a core problem with hair spray. Cores being toroids would often try to spin on the x, y & sense lines when they got double pulsed (a flip-the-bit write), after some time a turning core could wear through the enamel coating on the wires & short them. This engineer suggested that all core memory be sprayed with hair lacquer which of course sealed them & stopped them turning. He saved the company so much in repairs that they awarded him a 'bundle'. Cheers Doug
Post #33,154 by a6l6e6x 3/22/02 12:05:52 PM Reply	Yep, I hear about that Suggestion Award. Alex "Never express yourself more clearly than you think." -- Neils Bohr (1885-1962)
Post #33,225 by static 3/23/02 4:27:03 AM Reply	Question about core memory. Just how physically big was a single ferrite core in core memory? A few cm? Or less than a mm? Or were there several sizes? Wade, who has never seen real core memory. "All around me are nothing but fakes Come with me on the biggest fake of all!"
Post #33,229 by dmarker2 3/23/02 6:44:19 AM Reply	Re: Question about core memory. - My memory of core :-) This was invented by An Wang (later of WANG fame) There were several (3?) different sizes for the cores. 1400 family (IBM) had one size - System/360 had at least 2 sizes. The smallest I recall were so small we needed fine pointed tweezers to pick one up. These had to be about 0.5 mm Alex can you add any info ? Doug
Post #33,242 by Ashton 3/23/02 2:02:01 PM Reply	Now imagine threading R/W wires x-turns, through EACH one..
Post #33,263 by a6l6e6x 3/23/02 8:24:14 PM Reply	Re: core memory. The [link\|http://www.science.uva.nl/faculteit/museum/CoreMemory.html\|Core memory] I remember seeing used cores about 2 mm outside diameter. I'm sure some were much smaller. I also remember seeing some made of a ceramic bobbin with a metal tape wound on it. These were quite large ~5 mm and used to perform logic functions. These I saw during a summer job with Burroughs (which later merged with Sperry Rand) to form Unisys. Alex "Never express yourself more clearly than you think." -- Neils Bohr (1885-1962)
Post #33,309 by static 3/24/02 9:23:26 PM Reply	Ah... I have a hazy memory of a work colleague showing me an exposed minature core-memory in the late '80s. It all makes sense now. Wade. "All around me are nothing but fakes Come with me on the biggest fake of all!"

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