The Compact-Flash Wildcard and
CF Card Software Package User Guide

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CF Card Software

The CF Software Package comprises four layers. The first two are essentially invisible to the end user, and the latter two provide high level capabilities:

• The ATA/IDE software driver layer enables drive identification and read/write operations using standard ATA commands.



• The FAT layer implements a DOS-compatible FAT (File Allocation Table) file interface to track the placement of files on a pre-formatted ATA flash card in a PC-compatible format. Both FAT-12 and the newer FAT-16 formats are supported, and the FAT format is supported by all Microsoft operating systems including Windows NT, Windows 2000 and Windows XP. The key restrictions are that files must be in the root directory, and filenames are limited to the "8+3" scheme: up to 8 characters in the filename, and up to 3 characters in the file extension.



• The file management layer includes a set of user-callable commands modeled on the ANSI C file manipulation functions that enable the programmer to create, open, close, read, write, rename, copy and delete files in the root directory. Other software features include directory listing commands that behave like the DOS DIR command, a File_Type command that prints the contents of a specified file to the active serial port, and a File_Capture function to capture text sent from a terminal into a specified file. This set of functions allows files to be managed from within the QED environment and/or the PC environment. Files can be created on one platform and read and modified on the other.



• The automated file processing and redirection layer enables the programmer to specify a file to be automatically processed by the QED-Forth interpreter/compiler at startup. The software searches the root directory of a detected CF card for a file named "AUTOEXEC.QED" and, if it is found, interprets and executes the commands in the file. Two easy-to-use functions named Page_To_File and File_To_Page can be invoked in the autoexec file to store memory contents in a file, or transfer file contents to memory. This enables software upgrades to be performed in the field by simply plugging in a CF card that contains the proper update files. Finally, a powerful Redirect function allows any function to take its input from a specified file, and/or send its output to a specified file.

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