Desk Accessory - GEM

GEM

GEM resembled the Macintosh closely in many respects, and one of them was the presence of desk accessories, for the same reason: to allow multiple programs to be used in a system that only supported one full application at a time.

From a programming point of view, desk accessories were implemented, like other GEM applications, as DOS .EXE files, with names ending with .ACC (Accessory) rather than .APP (Application). Each .ACC file could support multiple accessories; all three of the standard GEM accessories (Calculator, Clock and Print Spooler) were provided by CALCLOCK.ACC. Installation was simply a matter of placing the .ACC in the correct directory - \GEMBOOT in earlier versions, and \GEMAPPS\GEMSYS in GEM/3 and later.

Since each DA loaded reduced the amount of memory available for programs, one technique for temporarily increasing available space was to rename one or more .ACC files to have a different suffix (usually .ACX) and restart GEM. On the Amstrad PC-1512, for example, the Snapshot accessory was shipped as SNAPSHOT.ACX and had to be renamed to .ACC if required.

Desk accessories continued to be supported in ViewMAX, the DR-DOS file manager, which was supplied with almost unchanged versions of Calculator and Clock.