/* */
/* (C) 2000 Freddy Offenga <taf_offenga@yahoo.com> */
/* 24-Jan-2011: Christian Krueger: Added defines for Antic instruction set */
-/* 2019-01-12: Bill Kendrick <nbs@sonic.net>: More defines for registers */
+/* 2019-01-16: Bill Kendrick <nbs@sonic.net>: More defines for registers */
/* */
/* */
/* This software is provided 'as-is', without any expressed or implied */
#ifndef __ANTIC_H
#define __ANTIC_H
-/* Define a structure with the ANTIC coprocessor's register offsets */
+/*****************************************************************************/
+/* Define a structure with the ANTIC coprocessor's register offsets */
+/*****************************************************************************/
+
struct __antic {
unsigned char dmactl; /* (W) direct memory access control */
+ unsigned char chactl; /* (W) character mode control */
+ unsigned char dlistl; /* display list pointer low-byte */
+ unsigned char dlisth; /* display list pointer high-byte */
+ unsigned char hscrol; /* (W) horizontal scroll enable */
+ unsigned char vscrol; /* (W) vertical scroll enable */
+ unsigned char unuse0; /* unused */
+ unsigned char pmbase; /* (W) msb of p/m base address (for when DMACTL has player and/or missile DMA enabled) */
+ unsigned char unuse1; /* unused */
+ unsigned char chbase; /* (W) msb of character set base address */
+ unsigned char wsync; /* (W) wait for horizontal synchronization */
+ unsigned char vcount; /* (R) vertical line counter */
+ unsigned char penh; /* (R) light pen horizontal position */
+ unsigned char penv; /* (R) light pen vertical position */
+ unsigned char nmien; /* (W) non-maskable interrupt enable */
+ union {
+ /* (W) ("NMIRES") nmi reset -- clears the interrupt request register;
+ ** resets all of the NMI status together
+ */
+ unsigned char nmires;
+
+ /* (R) ("NMIST") nmi status -- holds cause for the NMI interrupt */
+ unsigned char nmist;
+ };
+};
+
+
+/*****************************************************************************/
+/* DMACTL register options */
+/*****************************************************************************/
+
+/* Initialized to 0x22: DMA fetch, normal playfield, no PMG DMA, double-line PMGs */
/* Playfield modes: */
#define DMACTL_PLAYFIELD_NONE 0x00
#define DMACTL_PLAYFIELD_NARROW 0x01 /* e.g., 32 bytes per scanline with thick borders */
#define DMACTL_PLAYFIELD_NORMAL 0x02 /* e.g., 40 bytes per scanline with normal borders */
#define DMACTL_PLAYFIELD_WIDE 0x03 /* e.g., 48 bytes per scanline with no borders (overscan) */
+
/* Other options: */
-#define DMACTL_DMA_MISSILES 0x04 /* if not set, GTIA's GRAFP0 thru GRAFP3 used for player shapes; if set, ANTIC's PMBASE will be used to fetch shapes via DMA */
-#define DMACTL_DMA_PLAYERS 0x08 /* (ditto, using GTIA's GRAFM for missile shapes...) */
-#define DMACTL_PMG_SINGLELINE 0x10 /* if not set, default is double-scanline resolution PMGs */
-#define DMACTL_DMA_FETCH 0x20 /* if not set, disables ANTIC operation since it cannot fetch Display List instructions */
-/* Initialized to 0x22 (DMA fetch, normal playfield, no PMG DMA, double-line PMGs) */
+/* If not set, GTIA's GRAFP0 thru GRAFP3, and/or GRAFM registers are used for
+** player & missile shapes, respectively. (Modify the registers during the horizontal blank
+** (Display List Interrupt), a la "racing the beam" on an Atari VCS/2600, )
+** if set, ANTIC's PMBASE will be used to fetch shapes from memory via DMA.
+*/
+#define DMACTL_DMA_MISSILES 0x04
+#define DMACTL_DMA_PLAYERS 0x08
- unsigned char chactl; /* (W) character mode control */
+/* Unless set, PMGs (as fetched via DMA) will be double-scanline resolution */
+#define DMACTL_PMG_SINGLELINE 0x10
+
+/* Unless set, ANTIC operation is disabled, since it cannot fetch
+** Display List instructions
+*/
+#define DMACTL_DMA_FETCH 0x20
+
+
+/*****************************************************************************/
+/* CHACTL register options */
+/*****************************************************************************/
+
+/* Initialized to 2 (CHACTL_CHAR_NORMAL | CHACTL_INV_PRESENT) */
/* Inverted (upside-down) characters */
#define CHACTL_CHAR_NORMAL 0x00
#define CHACTL_CHAR_INVERTED 0x04
+
/* Inverse (reverse-video) characters */
#define CHACTL_INV_TRANS 0x00 /* chars with high-bit shown */
#define CHACTL_INV_OPAQUE 0x01 /* chars with high-bit appear as space */
#define CHACTL_INV_PRESENT 0x02 /* chars with high-bit are reverse-video */
-/* N.B. Default is "CHACTL_CHAR_NORMAL | CHACTL_INV_PRESENT", aka decimal 2 */
- unsigned char dlistl; /* display list pointer low-byte */
- unsigned char dlisth; /* display list pointer high-byte */
- unsigned char hscrol; /* (W) horizontal scroll enable */
- unsigned char vscrol; /* (W) vertical scroll enable */
- unsigned char unuse0; /* unused */
- unsigned char pmbase; /* (W) msb of p/m base address (for when DMACTL has player and/or missile DMA enabled) */
- unsigned char unuse1; /* unused */
- unsigned char chbase; /* (W) character set base address */
- unsigned char wsync; /* (W) wait for horizontal synchronization */
- unsigned char vcount; /* (R) vertical line counter */
- unsigned char penh; /* (R) light pen horizontal position */
- unsigned char penv; /* (R) light pen vertical position */
+/*****************************************************************************/
+/* Values for NMIEN (enabling interrupts) & NMIST (cause for the interrupt) */
+/*****************************************************************************/
- unsigned char nmien; /* (W) non-maskable interrupt enable */
+/* Display List Interrupts
+** Called on a modeline when "DL_DLI" bit is set the ANTIC instruction,
+** and jumps through VDSLST vector.
+*/
+#define NMIEN_DLI 0x80
-/* NMIEN settings: */
-#define NMIEN_DLI 0x80 /* see also: DL_DLI */
-#define NMIEN_VBI 0x40
-#define NMIEN_RESET 0x20
+/* Vertical Blank Interrupt
+** Called during every vertical blank; see SYSVBV, VVBLKI, CRITIC, and VVBLKD,
+** as well as the SETVBV routine.
+*/
+#define NMIEN_VBI 0x40
- unsigned char nmires; /* (W) ("NMIRES") nmi reset; (R) ("NMIST") nmi status */
-};
+/* [Reset] key pressed */
+#define NMIEN_RESET 0x20
-/* ANTIC instruction set */
+/*****************************************************************************/
+/* ANTIC instruction set */
+/*****************************************************************************/
/* Absolute instructions (non mode lines) */
#define DL_JMP ((unsigned char) 1)
#define DL_BLK7 ((unsigned char) 96)
#define DL_BLK8 ((unsigned char) 112)
+
/* Absolute instructions (mode lines) */
-/* Note: Actual width varies (e.g., 40 vs 32 vs 48) depending on normal vs narrow vs wide (overscan) playfield setting; see DMACTL */
+
+/* Note: Actual width varies (e.g., 40 vs 32 vs 48) depending on
+** normal vs narrow vs wide (overscan) playfield setting; see DMACTL
+*/
/* Character modes (text, tile graphics, etc.) */
-#define DL_CHR40x8x1 ((unsigned char) 2) /* monochrome, 40 character & 8 scanlines per mode line (aka Atari BASIC GRAPHICS 0 via OS's CIO routines) */
-#define DL_CHR40x10x1 ((unsigned char) 3) /* monochrome, 40 character & 10 scanlines per mode line (like GR. 0, with descenders) */
-#define DL_CHR40x8x4 ((unsigned char) 4) /* colour, 40 character & 8 scanlines per mode line (GR. 12) */
-#define DL_CHR40x16x4 ((unsigned char) 5) /* colour, 40 character & 16 scanlines per mode line (GR. 13) */
-#define DL_CHR20x8x2 ((unsigned char) 6) /* colour (duochrome per character), 20 character & 8 scanlines per mode line (GR. 1) */
-#define DL_CHR20x16x2 ((unsigned char) 7) /* colour (duochrome per character), 20 character & 16 scanlines per mode line (GR. 2) */
+
+/* monochrome, 40 character & 8 scanlines per mode line (aka Atari BASIC GRAPHICS 0 via OS's CIO routines) */
+#define DL_CHR40x8x1 ((unsigned char) 2)
+
+/* monochrome, 40 character & 10 scanlines per mode line (like GR. 0, with descenders) */
+#define DL_CHR40x10x1 ((unsigned char) 3)
+
+/* colour, 40 character & 8 scanlines per mode line (GR. 12) */
+#define DL_CHR40x8x4 ((unsigned char) 4)
+
+/* colour, 40 character & 16 scanlines per mode line (GR. 13) */
+#define DL_CHR40x16x4 ((unsigned char) 5)
+
+/* colour (duochrome per character), 20 character & 8 scanlines per mode line (GR. 1) */
+#define DL_CHR20x8x2 ((unsigned char) 6)
+
+/* colour (duochrome per character), 20 character & 16 scanlines per mode line (GR. 2) */
+#define DL_CHR20x16x2 ((unsigned char) 7)
+
/* Bitmap modes */
-#define DL_MAP40x8x4 ((unsigned char) 8) /* colour, 40 pixel & 8 scanlines per mode line (GR. 3) */
-#define DL_MAP80x4x2 ((unsigned char) 9) /* 'duochrome', 80 pixel & 4 scanlines per mode line (GR.4) */
-#define DL_MAP80x4x4 ((unsigned char) 10) /* colour, 80 pixel & 4 scanlines per mode line (GR.5) */
-#define DL_MAP160x2x2 ((unsigned char) 11) /* 'duochrome', 160 pixel & 2 scanlines per mode line (GR.6) */
-#define DL_MAP160x1x2 ((unsigned char) 12) /* 'duochrome', 160 pixel & 1 scanline per mode line (GR.14) */
-#define DL_MAP160x2x4 ((unsigned char) 13) /* 4 colours, 160 pixel & 2 scanlines per mode line (GR.7) */
-#define DL_MAP160x1x4 ((unsigned char) 14) /* 4 colours, 160 pixel & 1 scanline per mode line (GR.15) */
-#define DL_MAP320x1x1 ((unsigned char) 15) /* monochrome, 320 pixel & 1 scanline per mode line (GR.8) */
+
+/* colour, 40 pixel & 8 scanlines per mode line (GR. 3) */
+#define DL_MAP40x8x4 ((unsigned char) 8)
+
+/* 'duochrome', 80 pixel & 4 scanlines per mode line (GR.4) */
+#define DL_MAP80x4x2 ((unsigned char) 9)
+
+/* colour, 80 pixel & 4 scanlines per mode line (GR.5) */
+#define DL_MAP80x4x4 ((unsigned char) 10)
+
+/* 'duochrome', 160 pixel & 2 scanlines per mode line (GR.6) */
+#define DL_MAP160x2x2 ((unsigned char) 11)
+
+/* 'duochrome', 160 pixel & 1 scanline per mode line (GR.14) */
+#define DL_MAP160x1x2 ((unsigned char) 12)
+
+/* 4 colours, 160 pixel & 2 scanlines per mode line (GR.7) */
+#define DL_MAP160x2x4 ((unsigned char) 13)
+
+/* 4 colours, 160 pixel & 1 scanline per mode line (GR.15) */
+#define DL_MAP160x1x4 ((unsigned char) 14)
+
+/* monochrome, 320 pixel & 1 scanline per mode line (GR.8) */
+#define DL_MAP320x1x1 ((unsigned char) 15)
+
/* Equivalents, for people familiar with Atari 8-bit OS */
+
#define DL_GRAPHICS0 DL_CHR40x8x1
#define DL_GRAPHICS1 DL_CHR20x8x2
#define DL_GRAPHICS2 DL_CHR20x16x2
/* Modifiers to mode lines */
#define DL_HSCROL(x) ((unsigned char)((x) | 16)) /* enable smooth horizontal scrolling on this line; see HSCROL */
#define DL_VSCROL(x) ((unsigned char)((x) | 32)) /* enable smooth vertical scrolling on this line; see VSCROL */
-#define DL_LMS(x) ((unsigned char)((x) | 64)) /* Load Memory Scan (next two bytes must be the LSB/MSB of the data to load */
+#define DL_LMS(x) ((unsigned char)((x) | 64)) /* Load Memory Scan (next two bytes must be the LSB/MSB of the data to load) */
/* General modifier */
-#define DL_DLI(x) ((unsigned char)((x) | 128)) /* enable Display List Interrupt on this mode line; requires NMIEN set to enable DLIs */
-
+#define DL_DLI(x) ((unsigned char)((x) | 128)) /* enable Display List Interrupt on this mode line */
-/* Macros for the beginning and end of functions used as Display List Interrupts */
-#define DLI_START asm("pha"); asm("txa"); asm("pha"); asm("tya"); asm("pha");
-#define DLI_END asm("pla"); asm("tay"); asm("pla"); asm("tax"); asm("pla"); asm("rti");
/* End of _antic.h */
#endif /* #ifndef __ANTIC_H */
projects / cc65 / blobdiff