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Forum Index : Microcontroller and PC projects : Interesting magnetic core memory video...
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Grogster Admin Group  Joined: 31/12/2012 Location: New ZealandPosts: 9643 |
This is facinating... The first RAM chip Smoke makes things work. When the smoke gets out, it stops! |
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Justplayin Guru  Joined: 31/01/2014 Location: United StatesPosts: 330 |
I have a magnetic core memory board that I picked up back in the 70s. It looks really cool and makes a great conversation piece. I love showing it to the new technicians, their expressions when I tell them the whole board is a whopping 1K bits of storage. 
--Curtis I am not a Mad Scientist... It makes me happy inventing new ways to take over the world!! |
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| bigfix Senior Member  Joined: 20/02/2014 Location: AustriaPosts: 129 |
I still own a 16 Bit Minicomputer from DEC - PDP 11/34 with real core memory MM11DP with 16 Kilowords of Memory DEC's great innovation was the reduction of wires through the tiny cores to three They combined the Sense/Inhibit wire which was originally separate wires I did not switch it on the last 10 years - but maybe I should give it a try... Mass storage is 8" Floppies and 9 Track Tape |
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Zonker Guru Joined: 18/08/2012 Location: United StatesPosts: 772 |
Back when Lou and I were working at Elcom, we had an old terminal box and green CRT screen that was used for checking Rs-232 transaction terminals... The terminal video generator, (a board with maybe 30 IC's) used a 4 plane folded magnetic core memory, and another board full of chips to form the terminal... Lou replaced it with a TRS-80 box, which took way less space on the bench.. Wish I still had it... The mag-core planes were awesome to look at... |
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| Grogster Admin Group Joined: 31/12/2012 Location: New ZealandPosts: 9643 |
I love the way this guy explained it - historic, and very interesting. Well, to me anyway. 
"Hilda" must have had nimble fingers to be able to place all those cores and thread all those wires. Like most things of the period though, if you wanted it, you had to hand-build it. ...oh how far we have come... Despite the Back To The Future news items criticising that we don't have most of the stuff predicted in the films, we have made considerable leaps and bounds with technology since October the 21st, 1985!
Smoke makes things work. When the smoke gets out, it stops! |
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| Hatrick Newbie  Joined: 16/11/2015 Location: AustraliaPosts: 6 |
Ahh, memories! I have an old core memory board from a Nixdorf machine, which has 2k x 12bit words. Looks so cool that I framed it, entitled "Faded Memory" and it hangs on the wall of my den. If I was to power it up, it would still contain the last data written to it. I used to work on old Univac systems in the early 70s (418_III) as a hardware tech, and the core memory used banks of 16k x 18-bit words, expandable to a max of 128k, I recall. Cost was $1 per 18-bit word in 1970 dollars. They ran in octal rather than hex (easier to get your brain around octal). Huge cabinets, each with a 3v 100A(!) power supply. The only solid state memory was a small cache area running TTL chips. This was for speed as the core memory ran at about 750nS cycle time. The TTL cache chips were the only ICs in the mainframe, all the logic boards were discrete transistors. Interestingly, the logic was configured "upside down" in the sense that the power rail was -3v, with logic 1 (High) at 0v. I was told that the core matrices were hand-threaded in Hong Kong in those days, probably for two reasons; cheap labour and no OH&S issues. The workers could only do it for a couple of years before their eyesight started to fail! Gerry |
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boss Senior Member Joined: 19/08/2011 Location: CanadaPosts: 268 |
The SM/3 a Soviet equivalent of PDP 11/05 was my first computer I used on. The 32k Word of ferrite memory, one 2.5MB disk and single user DOS operating system. The console was VT52 compatible terminal made in Hungary. I was a SW engineer and technician in one person. The major advantage of the core memory was non volatility so in case the program or OS crashed you could start program counter from last successful instruction and let the program continue. And I was almost 40 years younger. 
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