Re: 100MHz TTL 6502: Here we go!
Posted: Sat Apr 24, 2021 12:38 am
Quick update:
Version 1.1 of the 65816 test suite is now complete. This new version takes four passes through all opcodes to test both zero and non-zero values for the DL and DH registers in turn. The code works perfectly on the Logisim model, including adding extra cycles when needed and saving them when possible. Hoglet was once again kind enough to run that test on his PiTubeDirect and Beeb816 and all passed as well. All great news.
The next step is to extend the suite to test the possible variations for the X, M and E flags. That’s a lot of extra validation, but it’s important to get it done. It’s pretty much now or never for the functionality in this design I suspect. There will be little hope of significant changes down the road, when signal integrity and timing become the main challenges.
Alright, more to come ...
Cheers for now,
Drass
Version 1.1 of the 65816 test suite is now complete. This new version takes four passes through all opcodes to test both zero and non-zero values for the DL and DH registers in turn. The code works perfectly on the Logisim model, including adding extra cycles when needed and saving them when possible. Hoglet was once again kind enough to run that test on his PiTubeDirect and Beeb816 and all passed as well. All great news.
The next step is to extend the suite to test the possible variations for the X, M and E flags. That’s a lot of extra validation, but it’s important to get it done. It’s pretty much now or never for the functionality in this design I suspect. There will be little hope of significant changes down the road, when signal integrity and timing become the main challenges.
Alright, more to come ...
Cheers for now,
Drass