Regenerative capacitor memory
Regenerative capacitor memory is a type of computer memory that uses the electrical property of capacitance to store the bits of data. Because the stored charge slowly leaks away, these memories must be periodically regenerated (i.e. read and rewritten, also called refreshed) to prevent data loss.
Other types of computer memory exist that use the electrical property of capacitance to store the data, but do not require regeneration. However these have either been somewhat impractical (e.g., the Selectron tube[1]) or are usually considered to be read-only memory (e.g., EPROM, Flash memory) because writing takes significantly longer than reading them.
History
The first regenerative capacitor memory built was the rotating capacitor drum memory of the Atanasoff–Berry Computer (1942). Each of its two drums stored thirty 50-bit binary numbers, rotated at 60 rpm and was regenerated every rotation (1 Hz refresh rate).
The first random access regenerative capacitor memory was the Williams tube (1947)[2]. Typically they stored 512 to 1024 bits, with the refresh rate required varied depending on the type of CRT used.
The modern DRAM (1966) is a regenerative capacitor memory[3].
References
- ↑ "Selectron tube". Virtual Exhibitions in Informatics. University of Klagenfurt. Retrieved 16 January 2018.
- ↑ Rajchman, Jan (23 August 1946). "Lecture 43 - The Selectron". The 1946 Moore School Lectures. RCA Laboratories, Princeton: Moore School of Electrical Engineering. Archived from the original on 2 June 2013.
- ↑ Klein, Dean A. "A History and Future of Memory Innovation". Semicon China. Micron Technology, Inc. Retrieved 16 January 2018.
Further reading
- Dekker, I.A.; Nieuwveld, W. A. C. (May 1964). "A capacitor memory for an analogue computer". Applied Scientific Research, Section B. Springer Netherlands. Volume 11 (Issue 3-4): 247–254. doi:10.1007/BF02922005. Retrieved 16 January 2018.