cc65/include/_pia.h

53 lines
3.0 KiB
C

/*****************************************************************************/
/* */
/* _pia.h */
/* */
/* Internal include file, do not use directly */
/* */
/* The Peripheral Interface Adapter (PIA) chip (a 6520 or 6820) provides */
/* parallel I/O interfacing; it was used in Atari 400/800 and Commodore PET */
/* family of computers, for joystick and some interrupts. */
/* Sources; various + Wikpedia article on "Peripheral Interface Adapter". */
/* */
/* */
/* (C) 2000 Freddy Offenga <taf_offenga@yahoo.com> */
/* */
/* */
/* This software is provided 'as-is', without any expressed or implied */
/* warranty. In no event will the authors be held liable for any damages */
/* arising from the use of this software. */
/* */
/* Permission is granted to anyone to use this software for any purpose, */
/* including commercial applications, and to alter it and redistribute it */
/* freely, subject to the following restrictions: */
/* */
/* 1. The origin of this software must not be misrepresented; you must not */
/* claim that you wrote the original software. If you use this software */
/* in a product, an acknowledgment in the product documentation would be */
/* appreciated but is not required. */
/* 2. Altered source versions must be plainly marked as such, and must not */
/* be misrepresented as being the original software. */
/* 3. This notice may not be removed or altered from any source */
/* distribution. */
/* */
/*****************************************************************************/
#ifndef __PIA_H
#define __PIA_H
/* Define a structure with the PIA register offsets */
struct __pia {
unsigned char porta; /* port A data r/w */
unsigned char portb; /* port B data r/w */
unsigned char pactl; /* port A control */
unsigned char pbctl; /* port B control */
};
/* (Some specific register values for Atari defined in atari.h) */
/* End of _pia.h */
#endif