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Diffstat (limited to 'bas.h')
| -rw-r--r-- | bas.h | 80 |
1 files changed, 80 insertions, 0 deletions
@@ -0,0 +1,80 @@ +/* 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 + +/* tokenized colon (statement separator) */ +#define TOK_COLON 0x14 + +/* 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 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 int verbose; + +extern void set_self(const char *argv0); +extern void die(const char *msg); +extern int 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 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); |