Bell System 1922 "computer logic" 4269

With a little help from Google I was able to answer my own question, as well as figure out why I couldn't easily find any reference to "iterative networks" in "Keister, Ritchie & Washburn". Apparently these networks were known as "reiterative networks", not "iterative networks", or at least "reiterative networks" is what "Keister, Ritchie & Washburn", as well as others call them.

I have another question for you though, you state that "the bidirectionality of transmission in a relay contact which is essential for an iterative network". Can you explain why "bidirectionality of transmission" is "essential for an iterative network"? After reading the discussion of "reiterative networks" in "Keister, Ritchie & Washburn" it is not clear to me why ordinary logic gates couldn't be used to implement the same "reiterative networks"?

As you say CMOS "bilateral gates" can be used to replace the relay contacts in a "reiterative network", and I have seen CMOS "bilateral gates" used for logic in the early 1970's. One CMOS "bilateral gate", or simple logic gate for that matter, only replaces a single pole relay contact, two CMOS "bilateral gates" are required to replace a double pole relay contact stack. It appears to me that simple logic gates can also replace the relay contacts in the "reiterative network" examples discussed in "Keister, Ritchie & Washburn", at least it worked for the examples I tried, although after taking a second look I do see at least one example where simple logic gates wouldn't work and "bidirectionality of transmission" would be required, however "bidirectionality of transmission" doesn't appear to be a requirement for "reiterative networks" in general, at least as "Keister, Ritchie & Washburn" describe them, and this seems consistent with the dictionary definition.

Regards,

John Byrns