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+f65 - "fake 6502" porting layer
+
+This is a set of C macros that implements most of the 6502 assembly
+language instructions, plus a perl script to convert 6502 assembly
+source to C code that calls the macros. You can use it to assist in
+porting 6502 assembly routines to C, using either the original asm
+source, or a disassembly created with da65.
+
+What's implemented: 64K of memory. The A/X/Y/S registers. The carry,
+zero, and negative flags. Most arithmetic and logic instructions. The
+stack. Conditional branches and absolute jumps are implemented as C
+goto's. JSR is implemented as a real C function call, and RTS is a
+real C return. Labels in the assembly source become C labels (aka goto
+targets). Equates in the asm source become C variables.
+
+What's not implemented: The D flag, and decimal mode in general. The
+V flag, and branches based on it. The I and B flags. Interrupts
+and the RTI instruction. The Program Counter (though branches, JMP,
+JSR, and RTS are implemented without it). ROM routines (including
+I/O). Indirect JMP. The "CPU bug" that causes e.g. 'LDA ($FF),y' to
+take its high byte from $00 rather than $100. (zeropage, x) addressing
+mode.
+
+I wrote this specifically to port the decompression algorithm from
+UnAlf 1.4. Instructions not used by UnAlf probably aren't implemented,
+or if they are, they're untested.
+
+The perl script doesn't magically convert a whole 6502 program to C
+source. You'll have to figure out which parts of the 6502 program are
+subroutines, and put them in their own C functions. Any data (.byte,
+.word, etc) won't be in the C program. Anything that does I/O must be
+rewritten in C.