Get Roped Into Magnetic Core Memory with this 512 bit Module https://hackaday.com/2025/07/11/get-roped-into-magnetic-core-memory-with-this-512-bit-module/ #Magnetic-corememory #Retrocomputing #corememory

Get Roped Into Magnetic Core Memory with this 512 bit Module - Magnetic Core memory was the RAM at the heart of many computer systems through the... - https://hackaday.com/2025/07/11/get-roped-into-magnetic-core-memory-with-this-512-bit-module/ #magnetic-corememory #retrocomputing #corememory

Thanks to a book recommendation by @bert_hubert [1], I went on a tangent learning more about the absolutely fascinating history and workings of core memory (and core rope memory, its read-only version). Some of this also very interesting for #PermaComputing and giving me ideas for future art projects...

Apollo Core Rope Memory (restoration and read out of 50 year old memory from the Apollo Guidance Computer)
https://www.youtube.com/watch?v=hckwxq8rnr0

Core Memory Explained and Demonstrated
https://www.youtube.com/watch?v=AwsInQLmjXc

[1] https://eupolicy.social/@bert_hubert/114760790691965256

Your Own Core Rope Memory - If you want read-only memory today, you might be tempted to use flash memory or, i... - https://hackaday.com/2025/05/14/your-own-core-rope-memory/ #retrocomputing #coreropememory #corememory #magnetics #memory

MUDs and the ability to reload new server without dropping connections (a “hotboot”)…

https://boston.conman.org/2025/02/11.2

…reminded me of an old RSX-11M application from an aeon ago, running part of a state government.

The app was too big for the PDP-11 (a common problem, as 32KW wasn't all that much even then), so the app removed the operating system from the computer, and ran, well, standalone.

Yes, you could do that back then.

That all worked swimmingly until somebody pressed ^C control-C on their terminal session, and the terminal driver then trapped into, well, nothingness.

Since the app code was too big for the PDP-11 it was running on, that smaller PDP-11 was shut down, the bigger local PDP-11 was switched over and re-booted and the app code loaded, and the bigger PDP-11 was then powered down.

The operator then pulled the core memory out of the bigger PDP-11, walked it over to the smaller PDP-11 and plugged it into the backplane, toggled in the address of the app's main loop onto the front panel switches, and toggled “go”, and off the smaller PDP-11 went running its too-big app.

Yeah, you could do a simple form of app checkpoint-restart with core memory, given core was persistent. And yeah, a bigger PDP-11 would have been helpful.

(Yes, SC was a creative administrator of those PDP-11 boxes. Swapping core never would have occurred to me.)

A Nibble Of Core Memory, In An SAO - Core memory, magnetised memory using tiny magnetic rings suspended on a grid of wi... - https://hackaday.com/2024/09/03/a-nibble-of-core-memory-in-an-sao/ #computerhacks #magneticcore #corememory #nibble

Inside a Mystery Aerospace Computer with [Ken Shirriff] https://hackaday.com/2024/06/01/inside-a-mystery-aerospace-computer-with-ken-shirriff/ #Retrocomputing #corememory #navigation #Signetics #avionics #computer #flight

Inside a Mystery Aerospace Computer with [Ken Shirriff] - When life hands you a mysterious bit of vintage avionics, your best bet to identif... - https://hackaday.com/2024/06/01/inside-a-mystery-aerospace-computer-with-ken-shirriff/ #retrocomputing #corememory #navigation #signetics #avionics #computer #flight

What’s a Transfluxor? - In the 1967 movie The Graduate, a wise older man gives some advice to the title ch... - https://hackaday.com/2024/03/03/whats-a-transfluxor/ #retrocomputing #transfluxor #corememory #parts #arma

Here is a link (cued to the time where it starts) of the best and most clear explanation of how core memory works. Reading & writing a bit has many steps!

Now I want to know how modern memory works with a similar level of detail.

I always felt there was something poetic about how one must destroy this kind of memory in order to read it. Observation is never passive... to observe a system is to change it... #computer #memory #history #coreMemory #cs

https://youtu.be/AwsInQLmjXc?list=TLPQMTcxMjIwMjPAV2NFeK1Otg&t=160

Saving Apollo by Decoding Core Rope - One of our favorite retro hardware enthusiasts, [CuriousMarc], is back with the ou... - https://hackaday.com/2023/11/04/saving-apollo-by-decoding-core-rope/ #apolloguidancecomputer #retrocomputing #coreropememory #corememory #history #agc

GLASNOST is a Computer That Makes Transparency A Priority - We live in a world where most of us take the transistor for granted. Within arm’s ... - https://hackaday.com/2023/07/17/glasnost-is-a-computer-that-makes-transparency-a-priority/ #computerhacks #corememory #vacuumtube #computer #glasnost #soviet #logic #gate

Supercon 2022: Andy Geppert is Bringing Core Memory Back - Many Hackaday readers will be familiar with the term “core memory”, likely thanks ... - https://hackaday.com/2023/05/18/supercon-2022-andy-geppert-is-bringing-core-memory-back/ #2022hackadaysupercon #magnetic-corememory #hackadaycolumns #retrocomputing #touchscreen #corememory #ledarray #core64 #cons

VCF East 2023: Andy Geppert Talks Core Memory - Do you know core memory? Our prehistoric predecessors would store data in the magn... - https://hackaday.com/2023/04/20/vcf-east-2023-andy-geppert-talks-core-memory/ #retrocomputing #vcfeast2023 #interviews #corememory