cdctap reads SIMH-format tape images that come from various Control Data Corporation (CDC) operating systems, primarily KRONOS and NOS, that were written in "I" (internal) format.
cdctap has options similar to the UNIX tar program for viewing tape contents and extracting items from the tape.
cdctap can extract the following CDC record types:
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Text and CCL "PROC" records: extracted as ASCII text. Translation uses 64-character display code by default, but 63-character and 6/12 display code are options.
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MODIFY OPL/OPLC and UPDATE sequential or random PL records: latest revision extracted as ASCII text, with or without sequence numbers. 6/12 display code translation is not supported for these record types. For an UPDATE sequential PL, the entire PL is extracted as a single file. For an UPDATE random PL record, the sequence number field currently contains a synthetic identifier name.
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PFDUMP and UMinn DUMPPF/ARCHIVE records: extracted as SIMH-format tape images in CDC "I" format. You can feed the resulting tape image through cdctap again to view and extract the contents of the permanent file. cdctap creates a separate directory per user index, e.g., the extracted permanent files from user index 377776 are placed in a subdirectory named "377776".
Tape images often contain multiple records with the same name, so cdctap chooses a unique name for each extracted record. For example, if "CIO.txt" already exists, cdctap will extract the next record named "CIO" to "CIO.1.txt".
You can specify the record names to be extracted using shell-type wildcards, e.g. "cmrd*". cdctap ignores upper/lower case when matching record names.
For PFDUMP and DUMPPF records, you can limit extraction to a particular user index via the syntax "ui/recname". Also, cdctap recognizes a small set of built-in user number to user index translations, e.g., "SYSTEMX" for user index 377777.
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SIMH tape format: http://www.bitsavers.org/pdf/simh/simh_magtape.pdf
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Control Data Corporation NOS: http://www.bitsavers.org/pdf/cdc/cyber/