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Some PIA register #defines

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Some register #defines for PIA.

(Some may be too Atari-centric -- I know PIA chip was used by PET &
perhaps other platforms supported by cc65.  If so, perhaps we can
define them elsewhere.  Not sure whether they'd be the same for 5200;
I admit I know zilch about that system except that it's _more or less_
an Atari 400)
This commit is contained in:
Bill Kendrick 2019-01-13 21:31:18 -08:00
parent 3783010091
commit 5ee3c88017
1 changed files with 36 additions and 4 deletions
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40
include/_pia.h
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@ -4,9 +4,14 @@
/* */
/* Internal include file, do not use directly */
/* */
/* The Peripheral Interface Adapter (PIA) chip provides parallel I/O */
/* interfacing; it was used in Atari 400/800 and Commodore PET family of */
/* computers, for joystick and interrupts. */
/* - Sources; various + Wikpedia article on "Peripheral Interface Adapter" */
/* */
/* */
/* (C) 2000 Freddy Offenga <taf_offenga@yahoo.com> */
/* 2019-01-13: Bill Kendrick <nbs@sonic.net>: Defines for registers */
/* */
/* */
/* This software is provided 'as-is', without any expressed or implied */
@ -34,18 +39,45 @@
#define __PIA_H
/* Define a structure with the pia register offsets */
/* Define a structure with the PIA register offsets */
struct __pia {
unsigned char porta; /* port A data r/w */
/* Paddle 0-3 triggers (per PORTA bits) */
#define PORTA_PTRIG3 0x80
#define PORTA_PTRIG2 0x40
#define PORTA_PTRIG1 0x08
#define PORTA_PTRIG0 0x04
unsigned char portb; /* port B data r/w */
/* Paddle 4-7 triggers (per PORTB bits); only 400/800 had four controller ports */
#define PORTB_PTRIG7 0x80
#define PORTB_PTRIG6 0x40
#define PORTB_PTRIG5 0x08
#define PORTB_PTRIG4 0x04
/* See also: "JOY_xxx_MASK" in "atari.h" */
unsigned char pactl; /* port A control */
unsigned char pbctl; /* port B control */
#define PxCTL_IRQ_ENABLE 0x01 /* (W) Peripheral A interrupt (IRQ) enable. */
/* One equals enable. Set by the OS but available to the user;
reset on powerup. */
#define PxCTL_BIT1 0x02 /* "Set to zero" */
#define PxCTL_ADDRESSING 0x04 /* (W) Controls PORTA addressing */
/* One equals PORTA register; zero equals direction control register */
#define PACTL_MOTOR_CONTROL 0x08 /* (W) Peripheral motor control line (turn the cassette on
or off; zero equals on) */
#define PBCTL_PERIPH_CMD_IDENT 0x08 /* Peripheral command identification (serial bus command) */
#define PxCTL_BIT4 0x10 /* "Set to one" */
#define PxCTL_BIT5 0x20 /* "Set to one" */
#define PxCTL_BIT6 0x40 /* "Set to zero" */
#define PxCTL_IRQ_STATUS 0x80 /* Peripheral interrupt (IRQ) status bit. */
/* Set by Peripherals (PORTA / PORTB). Reset by reading PORTA / PORTB*/
};
/* End of _pia.h */
#endif