/* */
/* 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" */
+/* 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> */
-/* 2019-01-13: Bill Kendrick <nbs@sonic.net>: Defines for registers */
/* */
/* */
/* This software is provided 'as-is', without any expressed or implied */
/* 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. */
};
+/* (Some specific register values for Atari defined in atari.h) */
+
/* End of _pia.h */
#endif