I searched the interrupt names, but none showed up except I have examined several redrawn visual 6502 pictures on this newsgroups. I want to know what exact interrupt name is.

I know what NMI and IRQ are. What are the last characters after names such as L, G, P like NMIL, NMIG, NMIP, IRQP, etc. What do characters stand for?

Take care,
Bryan Parkoff

Hi Bryan
you're asking about the naming conventions for internal signals in the visual6502. Most of the names were made up by Segher Boessenkool, I think. Anyone who isn't him, like you and me, have to guess what he was thinking of. L could be latch, and P could be pre, or pulse. G could be gated... (I don't think he's a member here, but he is on some mailing lists.)

Cheers
Ed

Hi Ed,

You might be right about the interrupt names. You and I and others are part of a team trying to figure out how each gate works. If anyone is already analyzed some gates, I am sure they will post their findings before more posts can be added in the visual 6502 notes.

Take care,
Bryan Parkoff

I just did some searching and found a couple of 6502 models by Clifford Wolf based on translations of the visual6502 netlists (I think so, anyway)
http://svn.clifford.at/handicraft/2013/logic6502/
http://svn.clifford.at/handicraft/2011/6502tsim/

In the more recent one there's a pointer to a paper: "Acyclic modeling of combinational loops" at http://ieeexplore.ieee.org/xpl/login.js ... er=1560091 (behind a paywall, but there's a later paper which addresses the topic at http://www.cs.columbia.edu/~sedwards/pa ... orming.pdf)


Cheers
Ed