Before magnetic and electronic memory, engineers solved the computing and memory challenge using punched cards. In the late 18th century to late 19th century, punched tapes and punched cards were used to “program” looms and other industrial machines. The technology was adapted for data storage for the 1890 census by Herman Hollerith. His initial designs held a 12 rows by 24 columns array of round holes. In 1928, IBM released an updated version with square holes in a 10 x 80 or 12 x 80 array. Capacity varied depending on the system – for the IBM 1401, for example, it took three columns to encode a 36-bit word. (Image courtesy of IBM)
Memory and disk space will both expand to overflow existing technology. At the time Bill made his statement, few of us had ever used more than 64K bytes of memory. It was only after memory prices fell that the great explosion began.
I remember when 8K by 16 bits cost $1/bit. Compare that to today's costs and you can see why Bill assumed the growth of memory would be limited.
By the way, I have a 16K by 16 bit ferrite bead board framed in my living room as an example of the past example of memory technology.
In addition to the magnetic core implementation shown, there were other variations according to the number of wires through each core. There were 2, 3, 4, and 5 wire varieties. In the 2-wire type, all the bits in a row are accessed at the same time. The Control Data Star-100 used this type of memory.
This was really interesting. Good work. I'm dubious of one stat, though: it doesn't seem possible that the magnetic drum rotated at 750,000 rotations per second. In fact, that most definitely can't be true.
Sometimes in my HDL code when I use a delay line or Johnson ring I call it a mercury line. It's the same concept. The springs in old reverb units are similar--they're basically FIFOs.
I actually "touched" magnetic core memory in the late 80's in a professional capacity. It was used in some Allan Bradley PLCs that were in an industrial plant I worked in as a student engineer. Hard to believe it was still in use as little as 25 years ago in functioning equipment.
hmmm. in the mid 80ies there was a type of Intel memory that acted as SRAM, but upon power failure was able to write the whole array into EEPROM or Flash cells, in parallel, before power was gone. don't remember the name though...
Sperry Univac had a drum memory that was ~6 feet in diameter and ~18 inchs wide. Had a head per track so no moving parts except the drum. Because of the large diameter it did not have to rotate very fast to get a high speed at the R/W head
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