Wikipedia:Reference desk/Archives/Computing/2019 February 12

= February 12 =

Batch command that returns drive size
Is there a batch command that returns drive size rather than just free space? Anna Frodesiak (talk) 01:52, 12 February 2019 (UTC)
 * On Windows? Have you tried "wmic logicaldisk get size,freespace,caption"? manya (talk) 05:02, 12 February 2019 (UTC)
 * Wow, thanks manya. That works. I never knew about wmic. (I'm running Win 10.) I'm not sure how to run it from a batchfile or make it output to a text file along with the date. Can it do that? (If that is an odd request, it is because I have a USB thumbdrive that I fill and empty a lot and wanted to track if its freespace got smaller each time.) Best, Anna Frodesiak (talk) 06:20, 12 February 2019 (UTC)
 * Try these two commands in a .cmd file which you can execute as script, but open log file with editor that supports unicode/encoded strings.
 * wmic logicaldisk get size,freespace,caption >> out.log
 * echo %date% %time% >> out.log
 * Hope this helps. manya (talk) 08:58, 12 February 2019 (UTC)
 * It's perfect, manya! Thank you so much. (I changed log to txt and that works fine.) Anna Frodesiak (talk) 10:00, 12 February 2019 (UTC)

How many square microns was the first SRAM cell?
SRAM was invented 1964 right? What was the process node? Sagittarian Milky Way (talk) 02:37, 12 February 2019 (UTC)


 * Who told you SRAM was invented in 1964? I believe that the Intel 3101 was the first IC RAM, and it came out in 1969. The 3101 die is roughly 2.39mm by 3.65mm. Feature size is about 12µm. --Guy Macon (talk) 06:19, 12 February 2019 (UTC)
 * claimed that. Sagittarian Milky Way (talk) 13:46, 12 February 2019 (UTC)


 * It claims that SRAM was invented in 1964, but does not claim that it was a silicon chip of any kind. Fairchild used Diode-Transistor circuits in 1964. They barely started working on integrated circuits when the main people left to form Intel. So, the first SRAM would have been made of a dense cluster of diodes and transistors. Fairchild did produce a SRAM array in 1967. I don't believe it was popular because upcoming computer devices used single-address memory produced in constantly improving models from 1968 onward. By 1969, the ex-Fairchild engineers were using silicon-gate technology to produce addressable RAM chips at Intel. 209.149.113.5 (talk) 18:45, 12 February 2019 (UTC)
 * Quote: The SRAM was invented at Fairchild Semiconductor in 1964 by an electrical engineer named John Schmidt. It was a 64-bit MOS p-channel SRAM. (my bolding) DroneB (talk) 18:46, 16 February 2019 (UTC)
 * You are talking about an early version of the Fairchild Semiconductor Advanced Memory (SAM), which was a hybrid memory, not a single integrated circuit. IIRC, Fairchild attached 64 of their 926 JK flip flop dies to a ceramic substrate and connected them with wire bonding. I believe that the same basic technology was used in the Apollo Guidance Computer, which used 4,100 three-input NOR gates. --Guy Macon (talk) 23:16, 16 February 2019 (UTC)
 * The datasheet shows integrated junction transistors not p-channel FETs. DroneB (talk) 19:25, 17 February 2019 (UTC)
 * Frankly, I don't care. The Intel 3101 was the first IC RAM, and it came out in 1969. Show me a data sheet For an integrated circuit RAM from 1965. chipsetc.com is a collector's blog. They usually get the details right but they are not infallible. --Guy Macon (talk) 01:49, 18 February 2019 (UTC)
 * Reading further, it looks like chipsetc.com got it right this time as well. From [ http://www.chipsetc.com/sram-memory.html ] (also see http://www.chipsetc.com/dram-memory.html ):
 * "The SRAM was invented at Fairchild Semiconductor in 1964 by an electrical engineer named John Schmidt. It was a 64-bit MOS p-channel SRAM. Intel released the first SRAM chip, the 256-bit Intel 1101 in 1969 . It used Schottky TTL (Transistor–Transistor Logic). Intel would go on to release the first DRAM memory chip, the Intel 1103, the next year in 1970."
 * I would like to see some info on that early Fairchild invention (which was most likely a one-off prototype) but it sure as hell wasn't an IC. --Guy Macon (talk) 02:00, 18 February 2019 (UTC)

I think in the 1960s, what you're calling SRAM (memory cells made of flip-flops, that I would have expected to be DTL or TTL rather than mosfets, but whatever) was so big and expensive that it would only have been used for machine registers (a few dozen words in a big computer). It was before my time but I believe there were IC flip-flops by the late 60s (or maybe earlier). However, that would mean a separate IC package per bit of memory (or maybe a few bits). Main memory would have been magnetic core memory, used about the same way that we use RAM now. 173.228.123.166 (talk) 06:46, 19 February 2019 (UTC)