ATPDraw includes the following files and documents:
•ATPDraw for Windows (ATPDraw.exe). Enables you to edit project files. Installation is not required; the exe-file can just be copied.
•ATPDraw Help (ATPDraw.chm). Describes how to use ATPDraw for Windows. The file is a compiled HTML file. Content will not show if run from a remote disc.
•Standard component library file (ATPDraw.scl). Contains zipped support files for standard components and TACS objects (299 in total). The support file contains information about the component data, node, icon and help.
•Initialization file (ATPDraw.ini). Contains customizable program options. This file can be used for configuration-free installation, but can otherwise be deleted. It is later stored in the %APPDATA%\ATPDraw directory.
When a component is added to the circuit the properties of the support file (icon, node and data layout) are copied to the data structure and thus become component properties. These properties can later on be changed locally using the Edit Definitions button. A reference to the original support file is kept in the project though.
From version 5.0 the project file follows the PKZIP 2 standard. From version 5.4 the project contains a single compressed file:
•Τhe circuit (.$$$). All components with their data, icon, position and connections along with circuit specific data like the values found under ATP|Settings. External data files (mod, lib, bct, xfr) are now included directly into each component's data structure.
As default the project files have extension acp (ATP circuit project).
When loading and building a circuit project all data (including lib-files) are stored internally in memory.
The single project file (acp) is sufficient for distributing the data case to other users.
When creating an ATP case (via ATP|Run ATP, or ATP|Sub-process|Make ATP file) all result files (lib-files + the main ATP file) is written to the same Result Directory as specified by the user. The default Result Directory is given under Tools|Options/Files&Folders-ATP folder, and a button 
on the toolbar is available to inspect and change it. Using ATP|Sub-process|Make ATP file will also change the Result Directory. The *.lib files (for lines&cables, user specified components, and windsyn components) are dumped from memory to disk each time the case is created. There is thus no more any risk of file sharing conflicts with other open projects. Since all $include files are stored in the same directory using the same extension (.lib) the Insert $prefix and $suffix cards can always be checked from ATP|Settings/Format. In order to avoid conflicts in names between lines&cables and user specified components the latter is proceeded with the letter 'u'. This is user editable from ATP|Settings/Format. With multiple runs and the Internal Parser results for run n are stored in ResultDir/n-1. The Result Directory easily is accumulated with multiple files. It is typically safe to delete all files from this directory as all data is stored in the projects. This does not apply of course if the user manually stores file here.
In the default directories the user can specify the structure of the global library. The specified paths appear as the default choice when the user tries to save data to disk (for instance when importing/exporting models, lcc, bctran, xfr, lib-files). The export/import feature is a special service and is not really needed.
Prior to version 5 the project files were zipped binary files (PKZIP 1 format) that contained information about the circuit, support file for non-standard components, and in addition external data files (models, user specified, bctran, lcc, xfmr, nonlinear characteristics). This is changed from version 5.