5493c9e7c2
The Receive Data Register and the Transmit Data Register share share a single address. Accessing that address with STA abs,X in order to fill the Transmit Data Register causes a 6502 false read which causes the Receive Data Register to be emptied. The simplest way to work around that issue - which I chose here - is to move the base address for all ACIA accesses from page $C0 to page $BF. However, that adds an additional cycle to all read accesses. An alternative approach would be to only modify the single line `sta ACIA_DATA,x`.
About cc65
cc65 is a complete cross development package for 65(C)02 systems, including a powerful macro assembler, a C compiler, linker, archiver and several other tools. cc65 has C and runtime library support for many of the old 6502 machines. For details look at the Website.
People
Core team members:
- Christian Groessler: Atari, Atari5200, and CreatiVision library Maintainer
- dqh: GHA help
- Greg King: all around hackery
- groepaz: CBM libary, Project Maintainer
- Oliver Schmidt: Apple II library Maintainer
External contributors:
- acqn: various compiler fixes
- jedeoric: Telestrat target
- jmr: compiler fixes
- karrika: Atari 7800 target
- Stephan Mühlstrasser: osic1p target
- Wayne Parham: Sym-1 target
(The above list is incomplete, if you feel left out - please speak up or add yourself in a PR)
For a complete list look at the full team list or the list of all contributors
Contact
For general discussion, questions, etc subscribe to the mailing list or use the github discussions.
Some of us may also be around on IRC #cc65 on libera.chat
Documentation
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The main Documentation for users and developers
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Info on Contributing to the CC65 project. Please read this before working on something you want to contribute, and before reporting bugs.
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The Wiki contains some extra info that does not fit into the regular documentation.
Downloads
