49 lines
1.7 KiB
Python
49 lines
1.7 KiB
Python
# mk_qd.py
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#
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# Make a blank QD (Quick Disk) image.
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#
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# Written & released by Keir Fraser <keir.xen@gmail.com>
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#
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# This is free and unencumbered software released into the public domain.
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# See the file COPYING for more details, or visit <http://unlicense.org>.
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import sys,struct,argparse
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def main(argv):
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parser = argparse.ArgumentParser(
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formatter_class=argparse.ArgumentDefaultsHelpFormatter)
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parser.add_argument("--lead-in", type=float, default=0.5,
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help="lead-in, seconds")
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parser.add_argument("--window", type=float, default=5.5,
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help="data window, seconds")
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parser.add_argument("--total", type=float, default=8.0,
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help="total length, seconds")
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parser.add_argument("outfile", help="output filename")
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args = parser.parse_args(argv[1:])
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bit_ms = 0.004916
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total_bytes = int(args.total * 1000.0 / bit_ms / 8)
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window_bytes = int(args.window * 1000.0 / bit_ms / 8)
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init_bytes = int(args.lead_in * 1000.0 / bit_ms / 8)
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assert (2*init_bytes + window_bytes) < total_bytes, "Window too large"
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print("Lead-In: %.2f sec -> %u bytes" % (args.lead_in, init_bytes))
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print("Window: %.2f sec -> %u bytes" % (args.window, window_bytes))
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print("TOTAL: %.2f sec -> %u bytes" % (args.total, total_bytes))
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# Header
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out_f = open(args.outfile, "wb")
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out_f.write(struct.pack("<3x2s3x", b"QD"))
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out_f.write(bytearray(b'\x00'*(512-8)))
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# Track
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out_f.write(struct.pack("<4I", 1024, total_bytes, init_bytes,
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init_bytes + window_bytes))
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out_f.write(bytearray(b'\x00'*(512-16)))
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# Data
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blocks = (total_bytes + 511) // 512
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out_f.write(bytearray(b'\x11'*(blocks*512)))
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if __name__ == "__main__":
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main(sys.argv)
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