My colleague Lane Mason found an interesting history of memories blog post that answers the question: ” What did early computers use for fast read/write storage?”
The post in the Hackaday blog, written by Al Williams, covers drum memories, the Williams Tube and its competitor the Selectron (both briefly discussed in my earlier 3D XPoint post), mercury delay lines, dekatrons, core memory (the original Storage Class Memory), plated wire memory, twistor memory, thin-film memory, and bubble memory.
It also links to interesting videos about these devices.
Think of this as a companion piece to the EE Times memory history slideshow I covered in an earlier post. It’s a fun and educational read!
With Micron & Intel’s July 28 introduction of their new 3D XPoint memory both companies touted that his is the first new memory in a long time, and that the list of prior new memory types is short.
How short is that list? Interestingly, Intel and Micron have different lists. The Micron list, shown in this post’s graphic (click to enlarge), cites seven types: “Ram” (showing a vacuum tube), PROM, SRAM, DRAM, EPROM, NOR flash, and NAND flash. Intel’s list adds magnetic bubble memory, making it eight. (Definitions of these names appear in another Memory Guy blog post.)
The Memory Guy finds both lists puzzling in that they left out a number of important technologies.
For example, why did Intel neglect EEPROM, which is still in widespread use? EEPROMs (or E²PROMs) are not only found in nearly every application that has a serial number (ranging from WiFi routers to credit cards), requires calibration (like blood glucose monitoring strips and printer ink cartridges), or provides operating parameters (i.e. the serial presence detect – SPD – in DRAM DIMMs), but they still ship in the billions of units every year. In its time EEPROM was an important breakthrough. Over the years EEPROM has had a much greater impact than has PROM.
And, given that both companies were willing to include tubes, a non-semiconductor technology, why did both Continue reading “How Many Kinds of Memory Are There?”
EE Times has published a very interesting slideshow called: A Brief History of Memory by Kristin Lewotsky. This is recommended reading for all who peruse of The Memory Guy blog. Even the comments are good reading, with one commenter sharing a history of ferroelectrics that dates back to the 1950s.
It’s interesting to see the Continue reading “History of Memory Slideshow in EE Times”
Nostalgia buffs who lived through computing in the 1970s will enjoy some magnificent photos shared in comments to a Microcontroller Central blog post. The photos, shared by Ryszard Milewicz, give a close-up view of a ferrite core memory plane. The photo from this blog is a part of one of Mr. Milewicz’ photos.
For those who were not exposed to core, this technology was based upon an approach in which every individual bit of a computer’s memory was a tiny donut made of compressed iron powder (“Ferrite”) that had to be hand strung with copper wire into a plane of bits.
A co-worker of The Memory Guy once had a high-speed memory array that he used as Continue reading “Remembering Core Memory”