/* 26 oct 2010 */

#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>

FILE *fin, *fout;

typedef uint8_t byte;
typedef uint16_t word;
typedef uint32_t ulong;

byte readbyte(void) { byte b; fread(&b, 1, 1, fin); return b; }
void writebyte(byte b) { fwrite(&b, 1, 1, fout); }
#define SEEK(k) fseek(fin, k, SEEK_SET)
#define TELL()  ftell(fin)

void getsamp(ulong start)
{
    word off, n;
    ulong saveaddr;
    ulong newaddr = 0;
    ulong bankbase = start & 0xFF8000;

    saveaddr = start;
    for (;;) {
        SEEK(saveaddr);
        off = readbyte();
        if (off == 0)
            break;
        off |= (readbyte() << 8);
        if (off != 0xFF)
            newaddr = bankbase + (off & 0x7FFF);
        n = readbyte();
        n |= (readbyte() << 8);
        readbyte(); readbyte(); /* skip speed and padding byte */
        saveaddr = TELL();
        SEEK(NEWADDR);
        for (; n; n--)
            writebyte(readbyte);
    }
}

int main(int argc, char *argv[])
{
    ulong addr;

    fin = fopen(argv[1], "rb");
    fout = fopen(argv[2], "wb");
    addr = strtoul(argv[3], NULL, 16);
    getsamp(addr);
    fclose(fin);
    fclose(fout);
    return 0;
}