From ab31b3edfebf5f54af71b4050bfc9cdae50b797f Mon Sep 17 00:00:00 2001 From: Bill Kendrick Date: Sun, 13 Jan 2019 00:31:31 -0800 Subject: [PATCH] Add more register #defines to ANTIC header file * DMACTL - playfield size, DMA access, PMG resolution * CHACTL - inverted text, inverse effects * NMIEN Also, added #define equivalents for Display List mode line instructions based on Atari 8-bit OS (aka Atari BASIC "GRAPHICS" command) values (e.g., "DL_GRAPHICS0" == "DL_CHR40x8x1"). Added some more documentation in the comments. Added macros with assembly language for the start/end of Display List Interrupt (DLI) functions. --- include/_antic.h | 130 +++++++++++++++++++++++++++++++++++++---------- 1 file changed, 103 insertions(+), 27 deletions(-) diff --git a/include/_antic.h b/include/_antic.h index 2aac3fccf..0d1bdaf65 100644 --- a/include/_antic.h +++ b/include/_antic.h @@ -5,9 +5,19 @@ /* Internal include file, do not use directly */ /* */ /* */ +/* "ANTIC 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 sprites 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" */ /* */ /* (C) 2000 Freddy Offenga */ /* 24-Jan-2011: Christian Krueger: Added defines for Antic instruction set */ +/* 2019-01-12: Bill Kendrick : More defines for registers */ /* */ /* */ /* This software is provided 'as-is', without any expressed or implied */ @@ -33,50 +43,86 @@ #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 */ + +/* 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) */ + + + unsigned char chactl; /* (W) character mode control */ + +/* 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; /* 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) 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 */ + +/* NMIEN settings: */ +#define NMIEN_DLI 0x80 /* see also: DL_DLI */ +#define NMIEN_VBI 0x40 +#define NMIEN_RESET 0x20 + + unsigned char nmires; /* (W) ("NMIRES") nmi reset; (R) ("NMIST") nmi status */ }; -/* antic instruction set */ +/* ANTIC instruction set */ -/* absolute instructions (non mode lines) */ +/* 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_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) */ -#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 */ +/* 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.) */ +#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) */ +/* 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) */ @@ -86,13 +132,43 @@ struct __antic { #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)) +/* 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; requires NMIEN set to enable DLIs */ + -/* general modifier */ -#define DL_DLI(x) ((unsigned char)((x) | 128)) +/* 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 */ -- 2.39.2