mtdump dumps the record structure of a tape image file in SIMH, E11, TPC, or P7B format. mtdump is invoked by: mtdump {-lsecp} file1 file2 file3... ...where -l specifies that dumping should stop at the first double-EOF mark or EOM mark, -s specifies standard SIMH format, -e specifies E11 format, -p specifies P7B format, and -c specifies TPC format. The default is to dump the entire file through the physical EOF in extended SIMH format. Output is to stdout, unless redirected. SIMH standard format is as follows: object object : and so on, where "objects" are either 4-byte metadata markers or data records of the form: 4 byte record length marker data bytes padded to even length if needed repeat of 4 byte record length marker The format defines three hexadecimal marker values: 00000000 = tape mark FFFFFFFE = erase gap FFFFFFFF = end of medium SIMH extended format is a superset of standard format that divides the metadata and length markers into two fields: a control class consisting of the upper four bits, and a marker-specific value or data-length value in the lower 28 bits. The control class values are further divided into private classes and SIMH-reserved classes. E11 format is similar to SIMH standard format, but odd-length data records are not padded to even lengths, and erase gap markers are not supported. TPC format is as follows: 2 byte record length 1 record 1 2 byte record length 2 record 2 : 2 bytes = 0000 for end of file and so on. Records are padded to even byte lengths. P7B format is confined to 7 track tapes and is as follows: start of record + first 6b character and parity : last character start of record + first 6b character and parity and so on. P7B data records consist 6-bit-plus-parity data bytes. The first record byte has the MSB set to indicate the start of the record, The remaining bytes omit this indicator. A P7B tape must end with a tape mark or a dummy "last record" indicator. A tape mark is indicated by a character of 217 octal (start of record, character 17, and incorrect odd parity or a reserved character for even parity). If a 217 tape mark is followed by additional "data" bytes of 017 octal value, the entire sequence is considered to be a single tape mark.