git.sur5r.net Git - cc65/blob - include/_pia.h

   1 /*****************************************************************************/
   2 /*                                                                           */
   3 /*                                  _pia.h                                   */
   4 /*                                                                           */
   5 /*                Internal include file, do not use directly                 */
   6 /*                                                                           */
   7 /* The Peripheral Interface Adapter (PIA) chip (a 6520 or 6820) provides     */
   8 /* parallel I/O interfacing; it was used in Atari 400/800 and Commodore PET  */
   9 /* family of computers, for joystick and some interrupts.                    */
  10 /* Sources; various + Wikpedia article on "Peripheral Interface Adapter".    */
  11 /*                                                                           */
  12 /*                                                                           */
  13 /* (C) 2000 Freddy Offenga <taf_offenga@yahoo.com>                           */
  14 /*                                                                           */
  15 /*                                                                           */
  16 /* This software is provided 'as-is', without any expressed or implied       */
  17 /* warranty.  In no event will the authors be held liable for any damages    */
  18 /* arising from the use of this software.                                    */
  19 /*                                                                           */
  20 /* Permission is granted to anyone to use this software for any purpose,     */
  21 /* including commercial applications, and to alter it and redistribute it    */
  22 /* freely, subject to the following restrictions:                            */
  23 /*                                                                           */
  24 /* 1. The origin of this software must not be misrepresented; you must not   */
  25 /*    claim that you wrote the original software. If you use this software   */
  26 /*    in a product, an acknowledgment in the product documentation would be  */
  27 /*    appreciated but is not required.                                       */
  28 /* 2. Altered source versions must be plainly marked as such, and must not   */
  29 /*    be misrepresented as being the original software.                      */
  30 /* 3. This notice may not be removed or altered from any source              */
  31 /*    distribution.                                                          */
  32 /*                                                                           */
  33 /*****************************************************************************/
  34
  35
  36
  37 #ifndef __PIA_H
  38 #define __PIA_H
  39
  40
  41 /* Define a structure with the PIA register offsets */
  42 struct __pia {
  43     unsigned char   porta;  /* port A data r/w */
  44     unsigned char   portb;  /* port B data r/w */
  45     unsigned char   pactl;  /* port A control */
  46     unsigned char   pbctl;  /* port B control */
  47 };
  48
  49 /* (Some specific register values for Atari defined in atari.h) */
  50
  51 /* End of _pia.h */
  52 #endif