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cube1us / IBM1410SMS

Database Program for capturing data from IBM SMS Automated Logic Diagrams and related database layer
GNU General Public License v3.0
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Report on wired or connections where two or more gates are not open collector #42

Closed cube1us closed 4 years ago

cube1us commented 4 years ago

Wired OR (connecting the outputs of two gates together) should imply that only one of them can be a non open collector gate. I have seen some examples where that is not the case:

Example: Machine 1411 page 11.10.02.1 between DEY 3B pin B and YLF 3D pin D.

Similarly, a non open-collector gate should really not be connected to a pull up (load pin) on another gate.

Develop a report on these - I would hope they are rare. (They could actually be design mistakes.)

cube1us commented 4 years ago

Closing this. The Wired OR check is in place. (However, note that the original IBM 1410 did violate this design rule at times - see the example in the comment from March 27).

Also checked are cases where a non open collector pin connects to load pin on the same gate.

NOT CHECKED: cases where a non open collector pin connects to a clamp or resistor that resides in a different gate. As a guess, most of those are either diode clamps (which are probably fine anyway), or load resistors that are associated with Wired OR connections, and thus are checked anway.