Table of Contents
General Use
Concepts and Terminology
Before using the functionality provided by CDC.IO, the terminology must be well-understood.
About Container Types
In general, commands operate on one of four types of virtual disk pack (container) objects:
- PLATO: A virtual device container which represents a PLATO Disk Device.
This type of container is free of any other operating system artifacts (as are found on NOS(1 or 2) disk packs) and is assumed to have a device geometry of an 844-type pack.
- NOS: A virtual device container which represents a properly formatted NOS1 or NOS2 pack.
- NovaNET: A host-based filesystem hierarchy which contains files in the format required by the NovaNET system.
- Backup: A host-based filesystem hierarchy which contains backup files written by this utility. Backup files may be restored to any supported device type. The backup hierarchy resembles, but is NOT the same as the NovaNET storage format.
Info
This utility currently operates on NOS Pack formats and correctly interprets label Level 0, 1 and 2.
The following pack geometries are automatically detected:
| Type | Model | Type | Model |
|---|---|---|---|
| DI | (844-21) | DJ | (844-41/Half-Track) |
| DL | (844-41/Full-Track) | DK | (7152/7154/844-21/Full-Track) |
| DM | (885) | DQ | (885) |
Although most FILE manipulations may be performed on individual packs, the NOS permanent file system enables the grouping of packs into families which must all be concurrently present when file operations are performed on pack families which have more than one member.
When a pack family has more than one member, the device number is automatically recognized by the utility, but no operations may be performed without the member which holds the family's catalog (the “table of contents” of the pack family).
NOS Files
Direct and Indirect access files are fully-supported, but functionality to manipulate them will be evolving over time, the primary objective was to get PLATO Master Files (and PLATO files) fully-supported first.
To facilitate family operations, and to enable bulk operations that span more than one pack of any type, the concept of a cluster is central to the context of this utility.
About Clusters
A cluster is (conceptually) a logical group of packs which have a relationship to each other in a system's running context.
A cluster collection is automatically discovered by scanning the contents of the path specified by the “-c” or “–cluster” command line option.
If the “cluster” (command line) option targets a file, that file is interpreted as as Cluster Definition File. This file associates a device number with a given virtual container.
Info
The use of this device number is planned for future functionality. The only requirement in the current implementation, is that these numbers are unique and their target containers are unique.
When “cluster” (command line) option targets a path, ALL files stored at that path are automatically examined and, if all automatic tests are satisfied, the pack is added to the cluster and made available for processing.
In the case of a NOS disk structure which contains PLATO Master Files, all PLATO Master Files are automatically sought and loaded into the cluster.
Clusters are useful when searching for, or manipulating files across multiple container files. This is especially helpful when only the filename is known (frequently the case with a PLATO system).
Detailed Command Reference
The Subcommand Reference contains all of the currently supported subcommands of CDC.IO.