1 /*****************************************************************************/
5 /* CPU core for the 6502 simulator */
9 /* (C) 2002 Ullrich von Bassewitz */
11 /* D-70597 Stuttgart */
12 /* EMail: uz@cc65.org */
15 /* This software is provided 'as-is', without any expressed or implied */
16 /* warranty. In no event will the authors be held liable for any damages */
17 /* arising from the use of this software. */
19 /* Permission is granted to anyone to use this software for any purpose, */
20 /* including commercial applications, and to alter it and redistribute it */
21 /* freely, subject to the following restrictions: */
23 /* 1. The origin of this software must not be misrepresented; you must not */
24 /* claim that you wrote the original software. If you use this software */
25 /* in a product, an acknowledgment in the product documentation would be */
26 /* appreciated but is not required. */
27 /* 2. Altered source versions must be plainly marked as such, and must not */
28 /* be misrepresented as being the original software. */
29 /* 3. This notice may not be removed or altered from any source */
32 /*****************************************************************************/
41 /*****************************************************************************/
43 /*****************************************************************************/
48 extern unsigned char AC; /* Accumulator */
49 extern unsigned char XR; /* X register */
50 extern unsigned char YR; /* Y register */
51 extern unsigned char SR; /* Status register */
52 extern unsigned char SP; /* Stackpointer */
53 extern unsigned PC; /* Program counter */
55 /* Status register bits */
56 #define CF 0x01 /* Carry flag */
57 #define ZF 0x02 /* Zero flag */
58 #define IF 0x04 /* Interrupt flag */
59 #define DF 0x08 /* Decimal flag */
60 #define BF 0x10 /* Break flag */
61 #define OF 0x40 /* Overflow flag */
62 #define SF 0x80 /* Sign flag */
66 /*****************************************************************************/
68 /*****************************************************************************/
73 /* Initialize the CPU */
89 /* End of cpucore.h */