3 ms·

Found on Figure 1-20, page 1-11 of the manual [1] [1] http://bitsavers.trailing-edge.com/pdf/ibm/logic/SY22-2798-2_LogicBlocks_AutomatedLogicDiagrams_SLT,SLD,A

Found on Figure 1-20, page 1-11 of the manual [1] [1] http://bitsavers.trailing-edge.com/pdf/ibm/logic/SY22-2798-2_LogicBlocks_AutomatedLogicDiagrams_SLT,SLD,ASLT,MST_TO_Oct71.pdf http://bitsavers.trailing-edge.com/pdf/ibm/logic/SY22-2798-2...

raverbashing 7y ago
This seems to be an older or non-standard FET depiction The modern symbol has an arrow and doesn't have a closed rectangle
- kens 7y ago
  Yes, this was IBM's symbol for a FET. They had their own nonstandard symbol for bipolar transistors too, three stacked boxes labeled N, P, N, with a triangle on the emitter. (See page 1-4 of the document above.) IBM also had their own logic gate symbols: an OR gate looked like an AND gate, and an AND gate looked like an op amp. I came across the FET joke while looking up IBM transistor symbols in response to TubeTime's thread on the history of transistor symbols (which is an interesting thread you should read): https://twitter.com/TubeTimeUS/status/1249023089528078337 https://twitter.com/TubeTimeUS/status/1249023089528078337
  - my_usernam3 7y ago
    Why is that? My "IBM is evil" bias leads me to guess they wanted to make their own standard that people started using. Then charge ridiculous license fees.
    - kens 7y ago
      I think several factors led to IBM's non-standard symbols. The standards didn't exist at the beginning, so different companies used different things. IBM also had historical baggage, wanting to stay consistent over time. In some ways IBM's symbols were better, for instance making NPN vs PNP obvious. Finally, IBM was big enough that they could do their own thing and train their own people.
  - amelius 7y ago
    Indeed an interestng thread, thanks!
  - drfuchs 7y ago
    IBM used all sorts of non-standard terminology of their own. You'd hear their folks seriously talking about PELs instead of Pixels ("Picture Elements"); and DASDs (pronounced "dah-z-dee") instead of disks ("Direct Access Storage Device"). Not clear if it was intentionally designed to be alienating to outsiders, but it sure seemed cultish.
- DanBC 7y ago
  I think it's a logic diagram, not an electrical symbol. For anyone looking for an explanation of the newer symbol, this is a nice source: https://www.petervis.com/electronics/MOSFET_Symbol/MOSFET_Symbol.html https://www.petervis.com/electronics/MOSFET_Symbol/MOSFET_Sy... Arrows were used in 1975, see page 57: https://www.noao.edu/ets/Mechanical/Policies/ANSI%20Y32.2-1975.pdf https://www.noao.edu/ets/Mechanical/Policies/ANSI%20Y32.2-19...

raverbashing 7y ago

This seems to be an older or non-standard FET depiction The modern symbol has an arrow and doesn't have a closed rectangle

kens 7y ago
Yes, this was IBM's symbol for a FET. They had their own nonstandard symbol for bipolar transistors too, three stacked boxes labeled N, P, N, with a triangle on the emitter. (See page 1-4 of the document above.) IBM also had their own logic gate symbols: an OR gate looked like an AND gate, and an AND gate looked like an op amp. I came across the FET joke while looking up IBM transistor symbols in response to TubeTime's thread on the history of transistor symbols (which is an interesting thread you should read): https://twitter.com/TubeTimeUS/status/1249023089528078337 https://twitter.com/TubeTimeUS/status/1249023089528078337
- my_usernam3 7y ago
  Why is that? My "IBM is evil" bias leads me to guess they wanted to make their own standard that people started using. Then charge ridiculous license fees.
  - kens 7y ago
    I think several factors led to IBM's non-standard symbols. The standards didn't exist at the beginning, so different companies used different things. IBM also had historical baggage, wanting to stay consistent over time. In some ways IBM's symbols were better, for instance making NPN vs PNP obvious. Finally, IBM was big enough that they could do their own thing and train their own people.
- amelius 7y ago
  Indeed an interestng thread, thanks!
- drfuchs 7y ago
  IBM used all sorts of non-standard terminology of their own. You'd hear their folks seriously talking about PELs instead of Pixels ("Picture Elements"); and DASDs (pronounced "dah-z-dee") instead of disks ("Direct Access Storage Device"). Not clear if it was intentionally designed to be alienating to outsiders, but it sure seemed cultish.
DanBC 7y ago
I think it's a logic diagram, not an electrical symbol. For anyone looking for an explanation of the newer symbol, this is a nice source: https://www.petervis.com/electronics/MOSFET_Symbol/MOSFET_Symbol.html https://www.petervis.com/electronics/MOSFET_Symbol/MOSFET_Sy... Arrows were used in 1975, see page 57: https://www.noao.edu/ets/Mechanical/Policies/ANSI%20Y32.2-1975.pdf https://www.noao.edu/ets/Mechanical/Policies/ANSI%20Y32.2-19...