Implement the zp,x version of BIT that's present on 65C02s #3
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
…e one in the eater.net kit.
This works on real hardware and is also used by Ben Eater's example programs (which always check the busy flag before sending an instruction).
… the program to execute. Switching to other modes (fast, slow, step) still works from this mode.
The first switches to TURBO clock speed and runs at that until it encounters a NOP, at which point it switches to STEP. It can't be triggered when the current instruction is a NOP. The second does the same thing, but switches back to STEP when encountering an RTS. For each JSR it encounters in the interim, it'll wait for an additional RTS, so the RTS where it switches to STEP should be the one from the current subroutine. It acts weirdly when triggered while the current instruction is a JSR for reasons I should look into but haven't yet. Both of these should potentially be homed in emu.c rather than gui.c, but they work for my purposes.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Opcode 0x34 was already mapped to BIT in opcodes.c, but it was missing elsewhere, resulting in... exciting behaviour.