File Conversion (FConvert)

Overview

The FConvert subcommand takes, as input, any valid file format and converts it to the requested format.

The general format may be found by invoking nosutils with the subcommand help switch -H (upper-case).

nosutils <inFile> <conversion_mode> <outFile> Extract contents from an input file <inFile> Convert contents as indicated by <conversion_mode> Write contents to an output file <outFile> Where: <conversion_mode> is: '60toDC' = 60 - bit Input to Display Code Output '60to64' = 60 - bit Input to 64 - bit Output '64toDC' = 64 - bit Input to Display Code Output '64to60' = 64 - bit Input to 60 - bit Output 'DCto60' = Display Code Input to 60 - Bit Output 'DCto64' = Display Code Input to 64 - Bit Output

Details

Warning

There are some (limited) safeguards built-in against converting invalid files.

It is assumed that the user understands the source/target forms of the files and is therefore the user's responsibility to ensure that the workstation's internal file formats are correct.

Significant testing of the conversion functions is performed prior to each release which verifies that back-and-forth conversions are accurate.

Notes:

In all conversions, signs and complement are not transformed and are assumed to be ones-complement values. This is intentional and enables external utilities to manipulate / interpret the original values as they existed in their 60-bit positions.
All little-endian (quad-word) results do not process the most significant four bits (they are disregarded and/or truncated).

60toDC/DCto60

60toDC The input file is read and each 24-bits of input is translated to 4 ASCII characters represending the corresponding CDC Display Code equivalent (6-bit) representation in the output file.

DCto60 The input file is read and each CDC Display Code equivalent represented by an ASCII (8-bit) character is packed, 6-bits at a time, into big-endian, 60-bit CM words.

60to64/64to60

60to64 The input file is read and each 60-bit, big-endian CM word (represented by 7.5 8-bit bytes) is rewritten as a little-endian representation of the CM Word in a series of 8, 8-bit bytes.

64to60 The input file is read and 8 byte, 8-bit, little-endian sequence is re-packed into 7.5 8-bit bytes representing a 60-bit, big-endian CM word.

64toDC/DCto64

64toDC The input file is read and each 64-bit little-endian quadword is processed as if it were a 60-bit, big-endian CM word (see 60toDC )

DCto64 The input file is read and each CDC Display Code equivalent represented by an ASCII (8-bit) character is processed (see DCto60 ) and a resulting 8-byte, 8-bits per byte, little-endian quadword is written to the output file.

Retro1.org codex

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