diff options
Diffstat (limited to 'bas.h')
| -rw-r--r-- | bas.h | 252 |
1 files changed, 252 insertions, 0 deletions
@@ -0,0 +1,252 @@ +/* bas.h - API for writing standalone programs that deal with + tokenized Atari 8-bit BASIC program. */ + +/* maximum size of the program in memory. 64KB is actually way overkill. */ +#define BUFSIZE 65536 + +/* the difference between the VVTP and VNTP values in the file, and the + actual file positions of the variable names and values. */ +#define TBL_OFFSET 0xf2 + +/* minimum program size, for a program that has no variables and + only one line of code (the immediate line 32768, consisting only of + one token, which would be CSAVE). anything smaller than this, we + can't process. */ +#define MIN_PROG_SIZE 21 + +/* maximum practical size for a BASIC program. if a file exceeds this + size, we warn about it, but otherwise process it normally. + this value is derived by subtracting the default LOMEM without DOS + ($0700) from the start of the display list in GR.0 ($9c20, on a 48K Atari). + */ +#define MAX_PROG_SIZE 38176 + +/* maximum number of variables in the variable name and value tables. this + could be 128, but "ERROR- 4" still expands the tables. Entries >128 + don't have tokens, can't be referred to in code, but we'll preserve + them anyway. */ +#define MAXVARS 256 + +/* BASIC tokens. Full set, taken from Chapter 10 of De Re Atari. + I used a paper copy, but you can also find it on the web: + https://www.atariarchives.org/dere/chapt10.php + BASIC uses 2 sets of tokens, one for commands and the other for + operators (which is to say, everything *not* a command). + See tokens.h for the actual names. */ + +/* commands (every statement begins with one of these) */ +#define CMD_REM 0x00 +#define CMD_DATA 0x01 +#define CMD_INPUT 0x02 +#define CMD_COLOR 0x03 +#define CMD_LIST 0x04 +#define CMD_ENTER 0x05 +#define CMD_LET 0x06 +#define CMD_IF 0x07 +#define CMD_FOR 0x08 +#define CMD_NEXT 0x09 +#define CMD_GOTO 0x0a +#define CMD_GO_TO 0x0b +#define CMD_GOSUB 0x0c +#define CMD_TRAP 0x0d +#define CMD_BYE 0x0e +#define CMD_CONT 0x0f +#define CMD_COM 0x10 +#define CMD_CLOSE 0x11 +#define CMD_CLR 0x12 +#define CMD_DEG 0x13 +#define CMD_DIM 0x14 +#define CMD_END 0x15 +#define CMD_NEW 0x16 +#define CMD_OPEN 0x17 +#define CMD_LOAD 0x18 +#define CMD_SAVE 0x19 +#define CMD_STATUS 0x1a +#define CMD_NOTE 0x1b +#define CMD_POINT 0x1c +#define CMD_XIO 0x1d +#define CMD_ON 0x1e +#define CMD_POKE 0x1f +#define CMD_PRINT 0x20 +#define CMD_RAD 0x21 +#define CMD_READ 0x22 +#define CMD_RESTORE 0x23 +#define CMD_RETURN 0x24 +#define CMD_RUN 0x25 +#define CMD_STOP 0x26 +#define CMD_POP 0x27 +#define CMD_QMARK 0x28 /* ? for PRINT */ +#define CMD_GET 0x29 +#define CMD_PUT 0x2a +#define CMD_GRAPHICS 0x2b +#define CMD_PLOT 0x2c +#define CMD_POSITION 0x2d +#define CMD_DOS 0x2e +#define CMD_DRAWTO 0x2f +#define CMD_SETCOLOR 0x30 +#define CMD_LOCATE 0x31 +#define CMD_SOUND 0x32 +#define CMD_LPRINT 0x33 +#define CMD_CSAVE 0x34 +#define CMD_CLOAD 0x35 +#define CMD_ILET 0x36 /* implied LET */ +#define CMD_ERROR 0x37 + +/* operators. 0x00-0x0d and 0x0a-0x11 are not used in Atari BASIC; + 0x0d is used (in the same way) in both Turbo BASIC and BXL/BXE. + 0x3d-0x54 are functions. */ +#define OP_HEXCONST 0x0d +#define OP_NUMCONST 0x0e +#define OP_STRCONST 0x0f +#define OP_COMMA 0x12 +#define OP_DOLLAR 0x13 +#define OP_EOS 0x14 /* two names: "end of statement"... */ +#define OP_COLON 0x14 /* ...and "colon" */ +#define OP_SEMICOLON 0x15 +#define OP_EOL 0x16 +#define OP_GOTO 0x17 +#define OP_GOSUB 0x18 +#define OP_TO 0x19 +#define OP_STEP 0x1a +#define OP_THEN 0x1b +#define OP_HASH 0x1c +#define OP_NUM_LE 0x1d +#define OP_NUM_NE 0x1e +#define OP_NUM_GE 0x1f +#define OP_NUM_LT 0x20 +#define OP_NUM_GT 0x21 +#define OP_NUM_EQ 0x22 +#define OP_POWER 0x23 +#define OP_MULT 0x24 +#define OP_PLUS 0x25 +#define OP_MINUS 0x26 +#define OP_DIVIDE 0x27 +#define OP_NOT 0x28 +#define OP_OR 0x29 +#define OP_AND 0x2a +#define OP_GRP_LPAR 0x2b +#define OP_GRP_RPAR 0x2c +#define OP_NUM_ASSIGN 0x2d +#define OP_STR_ASSIGN 0x2e +#define OP_STR_LE 0x2f +#define OP_STR_NE 0x30 +#define OP_STR_GE 0x31 +#define OP_STR_LT 0x32 +#define OP_STR_GT 0x33 +#define OP_STR_EQ 0x34 +#define OP_UPLUS 0x35 +#define OP_UMINUS 0x36 +#define OP_STR_LPAR 0x37 +#define OP_ARR_LPAR 0x38 +#define OP_DIM_ARR_LPAR 0x39 +#define OP_FUNC_LPAR 0x3a +#define OP_DIM_STR_LPAR 0x3b +#define OP_ARR_COMMA 0x3c /* used for A(1,1) or A$(1,1) (also in DIM) */ +#define OP_FUNC_STR 0x3d /* the rest are functions */ +#define OP_FUNC_CHR 0x3e +#define OP_FUNC_USR 0x3f +#define OP_FUNC_ASC 0x40 +#define OP_FUNC_VAL 0x41 +#define OP_FUNC_LEN 0x42 +#define OP_FUNC_ADR 0x43 +#define OP_FUNC_ATN 0x44 +#define OP_FUNC_COS 0x45 +#define OP_FUNC_PEEK 0x46 +#define OP_FUNC_SIN 0x47 +#define OP_FUNC_RND 0x48 +#define OP_FUNC_FRE 0x49 +#define OP_FUNC_EXP 0x4a +#define OP_FUNC_LOG 0x4b +#define OP_FUNC_CLOG 0x4c +#define OP_FUNC_SQR 0x4d +#define OP_FUNC_SGN 0x4e +#define OP_FUNC_ABS 0x4f +#define OP_FUNC_INT 0x50 +#define OP_FUNC_PADDLE 0x51 +#define OP_FUNC_STICK 0x52 +#define OP_FUNC_PTRIG 0x53 +#define OP_FUNC_STRIG 0x54 + +/* variable types, bits 6-7 of byte 0 of each vvtable entry. */ +#define TYPE_SCALAR 0 +#define TYPE_ARRAY 1 +#define TYPE_STRING 2 + +/* BASIC 14-byte header values */ +extern unsigned short lomem; +extern unsigned short vntp; +extern unsigned short vntd; +extern unsigned short vvtp; +extern unsigned short stmtab; +extern unsigned short stmcur; +extern unsigned short starp; + +/* positions where various parts of the file start, + derived from the header vars above. */ +extern unsigned short codestart; +extern unsigned short save_command_pos; +extern unsigned short save_command_tok; +extern unsigned short code_end; +extern unsigned short vnstart; +extern unsigned short vvstart; +extern int filelen; + +/* name of executable, taken from argv[0] */ +extern const char *self; + +/* entire file gets read into memory (for now) */ +extern unsigned char program[BUFSIZE]; + +/* file handles */ +extern FILE *input_file; +extern FILE *output_file; + +extern char *output_filename; + +extern int verbose; +extern int allow_hex_const; +extern int bxl_exttok_hack; +extern int numconst_size; +extern int error_token; + +extern void set_self(const char *argv0); +extern void die(const char *msg); +extern void parse_general_args(int argc, char **argv, void (*helpfunc)()); +extern int writefile(void); +extern void readfile(void); +extern unsigned short getword(int addr); +extern void setword(int addr, int value); +extern void dump_header_vars(void); +extern void parse_header(void); +extern void update_header(void); +extern void move_code(int offset); +extern void adjust_vntable_size(int oldsize, int newsize); +extern int vntable_ok(void); +extern unsigned char get_vartype(unsigned char tok); +extern void invalid_args(const char *arg); +extern FILE *open_file(const char *name, const char *mode); +extern void open_input(const char *name); +extern void open_output(const char *name); + +/* callback API begins here. + callbacks for walk_code(): */ +#define CALLBACK(x) void x(unsigned int lineno, unsigned int pos, unsigned int tok, unsigned int end) +#define CALLBACK_PTR(x) void (*x)(unsigned int lineno, unsigned int pos, unsigned int tok, unsigned int end) + +/* main entry point for callback API: */ +void walk_code(unsigned int startlineno, unsigned int endlineno); +#define walk_all_code() walk_code(0, 32768) + +/* available callbacks: */ +extern CALLBACK_PTR(on_start_line); +extern CALLBACK_PTR(on_bad_line_length); +extern CALLBACK_PTR(on_end_line); +extern CALLBACK_PTR(on_start_stmt); +extern CALLBACK_PTR(on_end_stmt); +extern CALLBACK_PTR(on_cmd_token); +extern CALLBACK_PTR(on_text); +extern CALLBACK_PTR(on_exp_token); +extern CALLBACK_PTR(on_var_token); +extern CALLBACK_PTR(on_string_const); +extern CALLBACK_PTR(on_num_const); +extern CALLBACK_PTR(on_trailing_garbage); |