Softdisk PC

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File Format
Name Softdisk PC
Released 1986

Softdisk PC was a diskmagazine of the 1980s and 1990s, which started in 1986 as Big Blue Disk and later became On Disk Monthly before settling into its final name of Softdisk PC. It ended publication in the late 1990s. It was one of the publications of Softdisk Publishing, which also included Softdisk for the Apple II, Loadstar for the Commodore, Softdisk for Mac (formerly Diskworld), Softdisk for Windows, Gamer's Edge, and PC BusinessDisk (and a few others).

It had various specialized file formats used in presenting its articles and menus, run through a "shell" program which presented the issue.

Early issues used a text-mode shell that worked on the whole range of PCs from non-graphical Monochrome Display Adapters (although these weren't officially supported because most other programs on the issues required graphics) to the various graphical adapters (CGA, EGA, VGA, SVGA). Later a new graphical shell was developed which required VGA or up. The storage medium for the issues also evolved with the times; originally one or more 360K 5 1/4" PC-format floppies, later a 3 1/2" 720K disk, and still later a CD-ROM with its whopping 600 megabytes or so of storage. While the floppy medium was still in use, compactness of size was of great importance, leading to the use of the Softdisk Text Compressor.

Various markup commands were embedded in the text files comprising magazine articles.



The CGA/EGA/text-mode issues (and a number of other Softdisk products, but not the later VGA issues) had a file called STATUS.DAT which was used to check on which issue (and which disk of a multi-disk issue) was inserted (for instance in order to tell whether the right disk was inserted or if the system needs to prompt the user to insert a different one), as well as to store some user settings. Since the system re-wrote the file regularly, occasionally something went wrong and clobbered it, which could interfere with the functioning of an issue (as it would then be unable to determine that the correct disk was inserted).

STATUS.DAT is a text file with one parameter per line in a fixed order. Over the history of its use, some new parameters were added on to the bottom of it, so the last lines didn't appear in early issues.

The lines are:

  • 1. "Status file for BIG BLUE DISK" (or various other product or company names after "Status file for"). Generally, programs that used this file checked for the string "Status file" to see whether it was a valid-format file.
  • 2. Name of publication: "BIG BLUE DISK", "Softdisk PC CGA/EGA", etc.
  • 3. Issue number.
  • 4. Issue date (e.g., "March 1990"). Was blank in later issues which no longer had an official date, as well as various undated products.
  • 5. Disk number within issue. (0 if entire issue was self-contained and no disk-swapping was necessary.)
  • 6. Current menu position. Used to save place in menu when the menu program exits to run another program on the issue, but needs to get back where it left off once the program exits.
  • 7. Text brightness setting. Where user could switch between light and dark text, this saved the current setting.
  • 8. Sound flag. Saved whether user turned off sound. Various programs might read this and honor the user setting.
  • 9. Version ID: indicates what version of the issue it is. (Some issues got remastered to fix bugs, etc.) The formatting of this varied over time.
  • 10. Tag line sometimes displayed in the menu, e.g., "The PC Software Subscription".
  • 11. Color setting (when user had choice of color schemes for menu).

Separator files

Softdisk diskmagazines had the files in their disk directories carefully arranged to put the files related to each program together (though they were all in the root directory of the disk; subdirectories were not generally used). The files for each item were separated by zero-length dummy files with lots of dashes in their names. (This was a tradition going back to earlier Softdisk publications for other platforms such as the Apple II and Commodore 64, which didn't support subdirectories in their disk filesystems.)

Of course, once you look at a Softdisk PC disk directory in Windows, that system "helpfully" sorts the directory for you, meaning that the related files are no longer necessarily together, and the separator files cluster uselessly.



See also

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