/* */
/* 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. */
+/* 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> */
-/* 2019-01-16: Bill Kendrick <nbs@sonic.net>: Defines for registers */
/* */
/* */
/* This software is provided 'as-is', without any expressed or implied */
unsigned char pbctl; /* port B control */
};
-
-/*****************************************************************************/
-/* PORTA and PORTB register bits */
-/*****************************************************************************/
-
-/* See also: "JOY_xxx_MASK" in "atari.h" */
-
-/* Paddle 0-3 triggers (per PORTA bits) */
-#define PORTA_PTRIG3 0x80
-#define PORTA_PTRIG2 0x40
-#define PORTA_PTRIG1 0x08
-#define PORTA_PTRIG0 0x04
-
-
-/* On the Atari 400/800, PORTB is the same as PORTA, but for controller ports 3 & 4. */
-
-/* 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
-
-
-/* On the XL series of computers, PORTB has been changed to a memory and
-** LED control (1200XL model only) register (read/write):
-*/
-
-/* If set, the built-in OS is enabled, and occupies the address range $C000-$FFFF
-** (except that the area $D000-$D7FF will only access the hardware registers.)
-** If clear, RAM is enabled in this area (again, save for the hole.)
-*/
-#define PORTB_OSROM 0x01
-
-/* If set, RAM is enabled for the address range $A000-$BFFF.
-** If clear, the built-in BASIC ROM is enabled at this address.
-** And if there is a cartridge installed in the computer, it makes no difference.
-*/
-#define PORTB_BASICROM 0x02
-
-/* If set, the corresponding LED is turned off. If clear, the LED will be on.
-** (1200XL only)
-*/
-#define PORTB_LED1 0x04
-#define PORTB_LED2 0x08
-
-
-/* On the XE series of computers, PORTB is a bank-selected memory control register (read/write): */
-
-/* These bits determine which memory bank is visible to the CPU and/or ANTIC chip
-** when their Bank Switch bit is set. There are four possible banks of 16KB each.
-*/
-#define PORTB_BANKSELECT1 0x00
-#define PORTB_BANKSELECT2 0x04
-#define PORTB_BANKSELECT3 0x08
-#define PORTB_BANKSELECT4 0x0C
-
-/* If set, the CPU and/or ANTIC chip will access bank-switched memory mapped to the
-** address range $4000-$7FFF.
-** If clear, the CPU and/or ANTIC will see normal memory in this region.
-*/
-#define PORTB_BANKSWITCH_CPU 0x10
-#define PORTB_BANKSWITCH_ANTIC 0x20
-
-/* If set, RAM is enabled for the address range $5000-$57FF.
-** If clear, the self-test ROM (physically located at $D000-$D7FF, under the hardware registers)
-** is remapped to this memory area.
-*/
-#define PORTB_SELFTEST 0x80
-
-
-/*****************************************************************************/
-/* PACTL and PBCTL register bits */
-/*****************************************************************************/
-
-/* (W) Peripheral A interrupt (IRQ) enable.
-** One equals enable. Set by the OS but available to the user; reset on powerup.
-*/
-#define PxCTL_IRQ_ENABLE 0x01
-
-/* "Set to zero" */
-#define PxCTL_BIT1 0x02
-
-/* (W) Controls PORTA addressing
-** One equals PORTA register; zero equals direction control register
-*/
-#define PxCTL_ADDRESSING 0x04
-
-#define PxCTL_BIT4 0x10 /* "Set to one" */
-#define PxCTL_BIT5 0x20 /* "Set to one" */
-#define PxCTL_BIT6 0x40 /* "Set to zero" */
-
-/* Peripheral interrupt (IRQ) status bit.
-** Set by Peripherals (PORTA / PORTB). Reset by reading PORTA / PORTB.
-*/
-#define PxCTL_IRQ_STATUS 0x80
-
-
-/* PACTL-specific register bit */
-
-/* (W) Peripheral motor control line
-** Turn the cassette on or off; zero equals on)
-*/
-#define PACTL_MOTOR_CONTROL 0x08
-
-
-/* PBCTL-specific register bit */
-
-/* Peripheral command identification (serial bus command) */
-#define PBCTL_PERIPH_CMD_IDENT 0x08
-
+/* (Some specific register values for Atari defined in atari.h) */
/* End of _pia.h */
#endif
projects / cc65 / blobdiff