Posts for defparam

Posted: 9/30/2015 9:06 PM
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defparam
Joined: 9/30/2015
Posts: 2
Masterjun wrote:
So is that code you're writing being executed on the original CPU? Where the game is also being executed? Because if that is the case, then console verification wouldn't be valid anymore, would it? Even little things can change the outcome drastically.
So i'm fairly new when it comes to the world of TAS but let me explain some potential configurations of this device that may satisfy for console verification. You have the device configured in a passive mode where if all you need is indication of when NMI occurs, or of when reading on the joystick port occurs then the FPGA can do that passively without injecting any code. If you do an active approach where say you have 1 small routine that is hooked at NMI, lets say for instance the routine adds an extra 20 bus cycles to every frame then you are looking at an overhead time of 6-8 microseconds lost per frame to overhead assuming a bus frequency of around 3MHz. (and of course the hook doesn't have to occur at every NMI).
Posted: 9/30/2015 4:54 PM
Post subject: SNES-Tap: a SNES console debugger via EXP port
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defparam
Joined: 9/30/2015
Posts: 2
Hey Guys, Some have you may or may not be aware of some of the SNES console work i've been doing using FPGAs. I set off on a mission last Jan to research the SNES EXP port to perform complete take over of the console to do things like load/save state, digital only graphics/audio output, etc... Since then I have created SNES-Tap which has the potential of doing all that and more. For more technical details on this device check out: http://forums.nesdev.com/viewtopic.php?f=12&t=13154 Here is what the device looks like: https://pbs.twimg.com/media/CMHYllaUkAAu17o.png Here is a current update of SNES-Tap showing its capability: https://www.youtube.com/watch?v=dE_q4EpsLco So long story short I want to continue work on this device and get it into key developers hands. Some of the items I want to tackle is load/save state on games like SMRPG, YI2, Starfox, etc... those games are particularly difficult because of the hardware co-processors. However, I also want to see how I can help out the TAS community. This device has complete access to read/write any system address, it knows the start of every frame and could be used as a meaningful tool for console verification. Let me know what you think, defparam