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Thanks for posting the link, that's pretty cool, but it leads to my question of how do you know they are correct approximations?

> That aside, I'm still wondering what you are on about. The "internal logic" of something like a 7400 is fully defined by the transistors, so to understand that, you have to understand how transistors work.

What I'm on about is precisely that the 'internal logic' of the 7400 is unknown and not fully defined.

You make an assumption here, that does not seem to be backed up by any published source, "it's fully defined by the transistors".

For example, it might very well be reliant on other aspects, such as the length of the circuit traces to function correctly.



https://www.ti.com/product/SN74LS00

Datasheet for a 7400 type chip (or actually multiple). Go check it out.


You linked to a completely different product, it says on the site "SN74LS00", "4-ch, 2-input, 4.75-V to 5.25-V bipolar NAND gates".

Are you getting confused as to what a bipolar NAND gate is vs. what we were discussing (the SN7400 TTL chip)?


https://www.ti.com/product/SN7400 is also "4-ch, 2-input, 4.75-V to 5.25-V bipolar NAND gates". I mentioned BJT and FET, for the latter there is https://www.ti.com/product/SN74AHCT00

Might be useful to know what BJT and FET means and then you will see that standard / original TTL is always "bipolar", for example.


Do you not realize that the design that TI currently sells is different from the 1965 design that we were discussing?

They are even manufactured using very different technology.

Like I said, just because it shares the same part number and is labelled "bipolar NAND gate" does not mean that it's approximately the same.


Well, this obviously has nothing to do with boot-up of a CPU anymore, either, so I'm out now.




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