This is the PDP-11 paper tape format, described in the DEC-11-GGPC-D PDP-11 "Paper Tape Software Programming Handbook" 1972.
The file starts with a character sequence which appears as an arrow when punched on 8-hole paper tape.
0x08, 0x1C, 0x2A, 0x49, 0x08, 0x00
Then follows a byte count, encoded big-endian in the low 4 bits of the next 4 bytes. The high bits should be zero.
Then follows a 0xFF byte.
The data follows, as many bytes as specified in the header.
The trailer consists of the following bytes:
and then a 2-byte checksum (big-endian).
The alternate header sequence
0x08, 0x1C, 0x3E, 0x6B, 0x08, 0x00
is followed by an 8-nibble big-endian byte count.
In general, binary data will expand in sized very little when represented with this format.
Here is a hex dump of a formatted binary file containing the data "Hello, World!".
0000: 08 1C 2A 49 08 00 00 00 ..*I.... 0008: 00 0E FF 48 65 6C 6C 6F ...Hello 0010: 2C 20 57 6F 72 6C 64 21 , World! 0018: 0A 00 00 04 73 ....s
srec_cat version 1.64
Copyright © 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014 Peter Miller
The srec_cat program comes with ABSOLUTELY NO WARRANTY; for details use the 'srec_cat -VERSion License' command. This is free software and you are welcome to redistribute it under certain conditions; for details use the 'srec_cat -VERSion License' command.