Timeline for Implementing three-state logic
Current License: CC BY-SA 4.0
9 events
| when toggle format | what | by | license | comment | |
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| Jan 12, 2023 at 20:50 | comment | added | davidcary | @SteveSh: do you have any more information about these 3 logic levels used in PROMs? It sounds related but not exactly the same as the 3 transistor sizes used to produce 4 voltage levels used in the 8087 microcode ROM in "high-density ROM in Intel's 8087 floating point chip". | |
| Oct 26, 2022 at 7:57 | comment | added | Rd Basha | See comments above | |
| Oct 26, 2022 at 2:59 | comment | added | jonk | @SteveSh I did make that assumption. And it could be that one of the trinary (balanced or otherwise) concepts was implied. That said, 'Rd' did happen to respond to the answer here discussing 3-state outputs and didn't disagree. So that may be a small bit of evidence to consider in addition to the question, itself. | |
| Oct 26, 2022 at 1:08 | comment | added | jsotola |
@RdBasha Do you have some source showing how it is built? ... you still have not clarified what you are actually asking about
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| Oct 25, 2022 at 23:57 | comment | added | SteveSh | @jonk - You're assuming that the hi-Z state is a 3rd logic level. I'm not sure that's what OP was asking about, and hence my first comment. Note that Intel way back in the 70's actually implemented ternary logic (3 voltage levels) in one of the PROMs ,IIRC. | |
| Oct 25, 2022 at 22:16 | comment | added | jonk | @RdBasha Wouldn't you just go to the Texas Instruments databook on the 7400 series devices and examine their schematics for "gates with 3-state outputs?" It's there, I believe. I forget what chapter, but it is roughly in the middle of the book. | |
| Oct 25, 2022 at 21:55 | history | edited | Justme | CC BY-SA 4.0 |
added 221 characters in body
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| Oct 25, 2022 at 21:21 | comment | added | Rd Basha | Thanks. Do you have some source showing how it is built? I know that I can just use the tools from Logisim, but I'm interested in building them myself fom scratch. | |
| Oct 25, 2022 at 21:17 | history | answered | Justme | CC BY-SA 4.0 |