1 /*****************************************************************************/
5 /* Internal include file, do not use directly */
8 /* "ANTIC, Alphanumeric Television Interface Controller, is responsible for */
9 /* the generation of playfield graphics which is delivered as a datastream */
10 /* to the related CTIA/GTIA chip. The CTIA/GTIA provides the coloring of the */
11 /* playfield graphics, and is responsible for adding overlaid sprite */
12 /* (referred to as "Player/Missile graphics" by Atari). Atari advertised it */
13 /* as a true microprocessor, in that it has an instruction set to run */
14 /* programs (called display lists) to process data. ANTIC has no capacity */
15 /* for writing back computed values to memory, it merely reads data from */
16 /* memory and processes it for output to the screen, therefore it is not */
17 /* Turing complete." - Wikipedia article on "ANTIC" (with edits) */
19 /* (C) 2000 Freddy Offenga <taf_offenga@yahoo.com> */
20 /* 24-Jan-2011: Christian Krueger: Added defines for Antic instruction set */
21 /* 2019-01-16: Bill Kendrick <nbs@sonic.net>: More defines for registers */
24 /* This software is provided 'as-is', without any expressed or implied */
25 /* warranty. In no event will the authors be held liable for any damages */
26 /* arising from the use of this software. */
28 /* Permission is granted to anyone to use this software for any purpose, */
29 /* including commercial applications, and to alter it and redistribute it */
30 /* freely, subject to the following restrictions: */
32 /* 1. The origin of this software must not be misrepresented; you must not */
33 /* claim that you wrote the original software. If you use this software */
34 /* in a product, an acknowledgment in the product documentation would be */
35 /* appreciated but is not required. */
36 /* 2. Altered source versions must be plainly marked as such, and must not */
37 /* be misrepresented as being the original software. */
38 /* 3. This notice may not be removed or altered from any source */
41 /*****************************************************************************/
47 /*****************************************************************************/
48 /* Define a structure with the ANTIC coprocessor's register offsets */
49 /*****************************************************************************/
52 unsigned char dmactl; /* (W) direct memory access control */
53 unsigned char chactl; /* (W) character mode control */
54 unsigned char dlistl; /* display list pointer low-byte */
55 unsigned char dlisth; /* display list pointer high-byte */
56 unsigned char hscrol; /* (W) horizontal scroll enable */
57 unsigned char vscrol; /* (W) vertical scroll enable */
58 unsigned char unuse0; /* unused */
59 unsigned char pmbase; /* (W) msb of p/m base address (for when DMACTL has player and/or missile DMA enabled) */
60 unsigned char unuse1; /* unused */
61 unsigned char chbase; /* (W) msb of character set base address */
62 unsigned char wsync; /* (W) wait for horizontal synchronization */
63 unsigned char vcount; /* (R) vertical line counter */
64 unsigned char penh; /* (R) light pen horizontal position */
65 unsigned char penv; /* (R) light pen vertical position */
66 unsigned char nmien; /* (W) non-maskable interrupt enable */
68 /* (W) ("NMIRES") nmi reset -- clears the interrupt request register;
69 ** resets all of the NMI status together
73 /* (R) ("NMIST") nmi status -- holds cause for the NMI interrupt */
79 /*****************************************************************************/
80 /* DMACTL register options */
81 /*****************************************************************************/
83 /* Initialized to 0x22: DMA fetch, normal playfield, no PMG DMA, double-line PMGs */
85 /* Playfield modes: */
86 #define DMACTL_PLAYFIELD_NONE 0x00
87 #define DMACTL_PLAYFIELD_NARROW 0x01 /* e.g., 32 bytes per scanline with thick borders */
88 #define DMACTL_PLAYFIELD_NORMAL 0x02 /* e.g., 40 bytes per scanline with normal borders */
89 #define DMACTL_PLAYFIELD_WIDE 0x03 /* e.g., 48 bytes per scanline with no borders (overscan) */
93 /* If not set, GTIA's GRAFP0 thru GRAFP3, and/or GRAFM registers are used for
94 ** player & missile shapes, respectively. (Modify the registers during the horizontal blank
95 ** (Display List Interrupt), a la "racing the beam" on an Atari VCS/2600, )
96 ** if set, ANTIC's PMBASE will be used to fetch shapes from memory via DMA.
98 #define DMACTL_DMA_MISSILES 0x04
99 #define DMACTL_DMA_PLAYERS 0x08
101 /* Unless set, PMGs (as fetched via DMA) will be double-scanline resolution */
102 #define DMACTL_PMG_SINGLELINE 0x10
104 /* Unless set, ANTIC operation is disabled, since it cannot fetch
105 ** Display List instructions
107 #define DMACTL_DMA_FETCH 0x20
110 /*****************************************************************************/
111 /* CHACTL register options */
112 /*****************************************************************************/
114 /* Initialized to 2 (CHACTL_CHAR_NORMAL | CHACTL_INV_PRESENT) */
116 /* Inverted (upside-down) characters */
117 #define CHACTL_CHAR_NORMAL 0x00
118 #define CHACTL_CHAR_INVERTED 0x04
120 /* Inverse (reverse-video) characters */
121 #define CHACTL_INV_TRANS 0x00 /* chars with high-bit shown */
122 #define CHACTL_INV_OPAQUE 0x01 /* chars with high-bit appear as space */
123 #define CHACTL_INV_PRESENT 0x02 /* chars with high-bit are reverse-video */
126 /*****************************************************************************/
127 /* Values for NMIEN (enabling interrupts) & NMIST (cause for the interrupt) */
128 /*****************************************************************************/
130 /* Display List Interrupts
131 ** Called on a modeline when "DL_DLI" bit is set the ANTIC instruction,
132 ** and jumps through VDSLST vector.
134 #define NMIEN_DLI 0x80
136 /* Vertical Blank Interrupt
137 ** Called during every vertical blank; see SYSVBV, VVBLKI, CRITIC, and VVBLKD,
138 ** as well as the SETVBV routine.
140 #define NMIEN_VBI 0x40
142 /* [Reset] key pressed */
143 #define NMIEN_RESET 0x20
146 /*****************************************************************************/
147 /* ANTIC instruction set */
148 /*****************************************************************************/
150 /* Absolute instructions (non mode lines) */
151 #define DL_JMP ((unsigned char) 1)
152 #define DL_JVB ((unsigned char) 65)
154 #define DL_BLK1 ((unsigned char) 0) /* 1 blank scanline */
155 #define DL_BLK2 ((unsigned char) 16) /* 2 blank scanlines */
156 #define DL_BLK3 ((unsigned char) 32) /* ...etc. */
157 #define DL_BLK4 ((unsigned char) 48)
158 #define DL_BLK5 ((unsigned char) 64)
159 #define DL_BLK6 ((unsigned char) 80)
160 #define DL_BLK7 ((unsigned char) 96)
161 #define DL_BLK8 ((unsigned char) 112)
164 /* Absolute instructions (mode lines) */
166 /* Note: Actual width varies (e.g., 40 vs 32 vs 48) depending on
167 ** normal vs narrow vs wide (overscan) playfield setting; see DMACTL
170 /* Character modes (text, tile graphics, etc.) */
172 /* monochrome, 40 character & 8 scanlines per mode line (aka Atari BASIC GRAPHICS 0 via OS's CIO routines) */
173 #define DL_CHR40x8x1 ((unsigned char) 2)
175 /* monochrome, 40 character & 10 scanlines per mode line (like GR. 0, with descenders) */
176 #define DL_CHR40x10x1 ((unsigned char) 3)
178 /* colour, 40 character & 8 scanlines per mode line (GR. 12) */
179 #define DL_CHR40x8x4 ((unsigned char) 4)
181 /* colour, 40 character & 16 scanlines per mode line (GR. 13) */
182 #define DL_CHR40x16x4 ((unsigned char) 5)
184 /* colour (duochrome per character), 20 character & 8 scanlines per mode line (GR. 1) */
185 #define DL_CHR20x8x2 ((unsigned char) 6)
187 /* colour (duochrome per character), 20 character & 16 scanlines per mode line (GR. 2) */
188 #define DL_CHR20x16x2 ((unsigned char) 7)
193 /* colour, 40 pixel & 8 scanlines per mode line (GR. 3) */
194 #define DL_MAP40x8x4 ((unsigned char) 8)
196 /* 'duochrome', 80 pixel & 4 scanlines per mode line (GR.4) */
197 #define DL_MAP80x4x2 ((unsigned char) 9)
199 /* colour, 80 pixel & 4 scanlines per mode line (GR.5) */
200 #define DL_MAP80x4x4 ((unsigned char) 10)
202 /* 'duochrome', 160 pixel & 2 scanlines per mode line (GR.6) */
203 #define DL_MAP160x2x2 ((unsigned char) 11)
205 /* 'duochrome', 160 pixel & 1 scanline per mode line (GR.14) */
206 #define DL_MAP160x1x2 ((unsigned char) 12)
208 /* 4 colours, 160 pixel & 2 scanlines per mode line (GR.7) */
209 #define DL_MAP160x2x4 ((unsigned char) 13)
211 /* 4 colours, 160 pixel & 1 scanline per mode line (GR.15) */
212 #define DL_MAP160x1x4 ((unsigned char) 14)
214 /* monochrome, 320 pixel & 1 scanline per mode line (GR.8) */
215 #define DL_MAP320x1x1 ((unsigned char) 15)
218 /* Equivalents, for people familiar with Atari 8-bit OS */
220 #define DL_GRAPHICS0 DL_CHR40x8x1
221 #define DL_GRAPHICS1 DL_CHR20x8x2
222 #define DL_GRAPHICS2 DL_CHR20x16x2
223 #define DL_GRAPHICS3 DL_MAP40x8x4
224 #define DL_GRAPHICS4 DL_MAP80x4x2
225 #define DL_GRAPHICS5 DL_MAP80x4x4
226 #define DL_GRAPHICS6 DL_MAP160x2x2
227 #define DL_GRAPHICS7 DL_MAP160x2x4
228 #define DL_GRAPHICS8 DL_MAP320x1x1
229 #define DL_GRAPHICS9 DL_MAP320x1x1 /* N.B.: GRAPHICS 9, 10, and 11 also involve GTIA's PRIOR register */
230 #define DL_GRAPHICS10 DL_MAP320x1x1
231 #define DL_GRAPHICS11 DL_MAP320x1x1
232 #define DL_GRAPHICS12 DL_CHR40x8x4 /* N.B.: Atari 400/800 OS didn't have GRAPHICS 12 or 13 */
233 #define DL_GRAPHICS13 DL_CHR40x16x4
234 #define DL_GRAPHICS14 DL_MAP160x1x2
235 #define DL_GRAPHICS15 DL_MAP160x1x4
237 /* Atari 400/800 OS didn't have GRAPHICS 14 or 15, so they were known by "6+" and "7+" */
238 #define DL_GRAPHICS6PLUS DL_GRAPHICS14
239 #define DL_GRAPHICS7PLUS DL_GRAPHICS15
241 /* Neither Atari 400/800 nor XL OS supported 10-scanline (descenders) text mode via CIO */
242 #define DL_GRAPHICS0_DESCENDERS DL_CHR40x10x1
244 /* Modifiers to mode lines */
245 #define DL_HSCROL(x) ((unsigned char)((x) | 16)) /* enable smooth horizontal scrolling on this line; see HSCROL */
246 #define DL_VSCROL(x) ((unsigned char)((x) | 32)) /* enable smooth vertical scrolling on this line; see VSCROL */
247 #define DL_LMS(x) ((unsigned char)((x) | 64)) /* Load Memory Scan (next two bytes must be the LSB/MSB of the data to load) */
249 /* General modifier */
250 #define DL_DLI(x) ((unsigned char)((x) | 128)) /* enable Display List Interrupt on this mode line */
253 /* End of _antic.h */
254 #endif /* #ifndef __ANTIC_H */