128991d868
On C64, VIC-20 and Plus/4, the conio library PLOT routine uses direct calls into the Kernal, including the Kernal PLOT routine that we're replacing. These were previously hardcoded addresses; we change these to use the symbols for those routines defined in cbm_kernal.inc. (This changes no functionality.) To do this, we need to import cbm_kernal.inc in a namespace so we don't have a collision between the PLOT that we're defining and the Kernal definition. We also add a UPDCRAMPTR symbol (used by kplot for VIC-20 and C64) to the direct entry kernal routines in in cbm_kernal.inc, and expand the comments describing what the "direct entry" Kernal routines are. <greg.king5@verizon.net> (GitHub: greg-king5) came up with this idea and did initial testing of it. This has been tested on VICE xvic, x64 and xplus4 emulators with a program that does a cputs() call (github.com/0cjs/vic20cc65) to confirm that it works the same way after as it did before.
cc65 is a complete cross development package for 65(C)02 systems, including a powerful macro assembler, a C compiler, linker, librarian and several other tools.
cc65 has C and runtime library support for many of the old 6502 machines, including
- the following Commodore machines:
- VIC20
- C16/C116 and Plus/4
- C64
- C128
- CBM 510 (aka P500)
- the 600/700 family
- newer PET machines (not 2001).
- the Apple ][+ and successors.
- the Atari 8 bit machines.
- the Atari 2600 console.
- the Atari 5200 console.
- GEOS for the C64, C128 and Apple //e.
- the Bit Corporation Gamate console.
- the NEC PC-Engine (aka TurboGrafx-16) console.
- the Nintendo Entertainment System (NES) console.
- the Watara Supervision console.
- the VTech Creativision console.
- the Oric Atmos.
- the Oric Telestrat.
- the Lynx console.
- the Ohio Scientific Challenger 1P.
The libraries are fairly portable, so creating a version for other 6502s shouldn't be too much work.