File Format: Enterprise EPTE

EPTE is a capture of the byte stream that is encoded on a tape, along with a table of pointers to demarcate individual data chunks. It is not formally documented.

EPTE files usually have the file extension .tap.

Detection

EPTEs have the 32-byte long ASCII string ENTERPRISE 128K TAPE FILE padded on the right with spaces stored at offset 128 in the file.

Parsing

Header

The first 128 bytes of the file are up to 32 little endian four-byte pointers to tape chunks within the file. These pointers are unsigned and relative to file location 512.

It is unknown whether the bytes after the signature string but before location 512 have any meaning.

Reconstruction

For each identified chunk, output:

1. lead-in tone, including a sync bit;
2. the encoded form of the data that comprises the chunk.