/* Internal include file, do not use directly */
/* */
/* */
+/* "ANTIC, Alphanumeric Television Interface Controller, is responsible for */
+/* the generation of playfield graphics which is delivered as a datastream */
+/* to the related CTIA/GTIA chip. The CTIA/GTIA provides the coloring of the */
+/* playfield graphics, and is responsible for adding overlaid sprite */
+/* (referred to as "Player/Missile graphics" by Atari). Atari advertised it */
+/* as a true microprocessor, in that it has an instruction set to run */
+/* programs (called display lists) to process data. ANTIC has no capacity */
+/* for writing back computed values to memory, it merely reads data from */
+/* memory and processes it for output to the screen, therefore it is not */
+/* Turing complete." - Wikipedia article on "ANTIC" (with edits) */
/* */
/* (C) 2000 Freddy Offenga <taf_offenga@yahoo.com> */
/* 24-Jan-2011: Christian Krueger: Added defines for Antic instruction set */
+/* 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 register offsets */
+/*****************************************************************************/
+/* Define a structure with the ANTIC coprocessor's register offsets */
+/*****************************************************************************/
+
struct __antic {
- unsigned char dmactl; /* direct memory access control */
- unsigned char chactl; /* character mode control */
+ 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; /* horizontal scroll enable */
- unsigned char vscrol; /* vertical scroll enable */
+ unsigned char hscrol; /* (W) horizontal scroll enable */
+ unsigned char vscrol; /* (W) vertical scroll enable */
unsigned char unuse0; /* unused */
- unsigned char pmbase; /* msb of p/m base address */
+ 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; /* character base address */
- unsigned char wsync; /* wait for horizontal synchronization */
- unsigned char vcount; /* vertical line counter */
- unsigned char penh; /* light pen horizontal position */
- unsigned char penv; /* light pen vertical position */
- unsigned char nmien; /* non-maskable interrupt enable */
- unsigned char nmires; /* nmi reset/status */
+ 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;
+ };
};
-/* antic instruction set */
-
-/* absolute instructions (non mode lines) */
-#define DL_JMP (unsigned char) 1
-#define DL_JVB (unsigned char) 65
-
-#define DL_BLK1 (unsigned char) 0
-#define DL_BLK2 (unsigned char) 16
-#define DL_BLK3 (unsigned char) 32
-#define DL_BLK4 (unsigned char) 48
-#define DL_BLK5 (unsigned char) 64
-#define DL_BLK6 (unsigned char) 80
-#define DL_BLK7 (unsigned char) 96
-#define DL_BLK8 (unsigned char) 112
-
-/* absolute instructions (mode lines) */
-#define DL_CHR40x8x1 (unsigned char) 2 /* monochrome, 40 character & 8 scanlines per mode line (GR. 0) */
-#define DL_CHR40x10x1 (unsigned char) 3 /* monochrome, 40 character & 10 scanlines per mode line */
-#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) */
-
-#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) */
-
-/* modifiers on mode lines */
-#define DL_HSCROL(x) (unsigned char)((x) | 16)
-#define DL_VSCROL(x) (unsigned char)((x) | 32)
-#define DL_LMS(x) (unsigned char)((x) | 64)
-
-/* general modifier */
-#define DL_DLI(x) (unsigned char)((x) | 128)
+/*****************************************************************************/
+/* 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: */
+
+/* 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
+
+/* 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 */
+
+
+/*****************************************************************************/
+/* Values for NMIEN (enabling interrupts) & NMIST (cause for the interrupt) */
+/*****************************************************************************/
+
+/* 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
+
+/* Vertical Blank Interrupt
+** Called during every vertical blank; see SYSVBV, VVBLKI, CRITIC, and VVBLKD,
+** as well as the SETVBV routine.
+*/
+#define NMIEN_VBI 0x40
+
+/* [Reset] key pressed */
+#define NMIEN_RESET 0x20
+
+
+/*****************************************************************************/
+/* ANTIC instruction set */
+/*****************************************************************************/
+
+/* Absolute instructions (non mode lines) */
+#define DL_JMP ((unsigned char) 1)
+#define DL_JVB ((unsigned char) 65)
+
+#define DL_BLK1 ((unsigned char) 0) /* 1 blank scanline */
+#define DL_BLK2 ((unsigned char) 16) /* 2 blank scanlines */
+#define DL_BLK3 ((unsigned char) 32) /* ...etc. */
+#define DL_BLK4 ((unsigned char) 48)
+#define DL_BLK5 ((unsigned char) 64)
+#define DL_BLK6 ((unsigned char) 80)
+#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
+*/
+
+/* Character modes (text, tile graphics, etc.) */
+
+/* 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 */
+
+/* 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
+#define DL_GRAPHICS3 DL_MAP40x8x4
+#define DL_GRAPHICS4 DL_MAP80x4x2
+#define DL_GRAPHICS5 DL_MAP80x4x4
+#define DL_GRAPHICS6 DL_MAP160x2x2
+#define DL_GRAPHICS7 DL_MAP160x2x4
+#define DL_GRAPHICS8 DL_MAP320x1x1
+#define DL_GRAPHICS9 DL_MAP320x1x1 /* N.B.: GRAPHICS 9, 10, and 11 also involve GTIA's PRIOR register */
+#define DL_GRAPHICS10 DL_MAP320x1x1
+#define DL_GRAPHICS11 DL_MAP320x1x1
+#define DL_GRAPHICS12 DL_CHR40x8x4 /* N.B.: Atari 400/800 OS didn't have GRAPHICS 12 or 13 */
+#define DL_GRAPHICS13 DL_CHR40x16x4
+#define DL_GRAPHICS14 DL_MAP160x1x2
+#define DL_GRAPHICS15 DL_MAP160x1x4
+
+/* Atari 400/800 OS didn't have GRAPHICS 14 or 15, so they were known by "6+" and "7+" */
+#define DL_GRAPHICS6PLUS DL_GRAPHICS14
+#define DL_GRAPHICS7PLUS DL_GRAPHICS15
+
+/* Neither Atari 400/800 nor XL OS supported 10-scanline (descenders) text mode via CIO */
+#define DL_GRAPHICS0_DESCENDERS DL_CHR40x10x1
+
+/* 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) */
+
+/* General modifier */
+#define DL_DLI(x) ((unsigned char)((x) | 128)) /* enable Display List Interrupt on this mode line */
+
/* End of _antic.h */
#endif /* #ifndef __ANTIC_H */
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