This program receives external commands and acts on them. Under normal circumstances, STD DOS is invisible to the user and no console or external disks are required. Every SMC has two serial lines. If the application program is aborted, the SMC becomes a full-fledged DOS computer, using the console, keyboard and disks of the external computer through VSC and the communication line. The laptop's disk can be accessed by both the laptop and the SMC, permitting programs to be transferred easily between them.
Source code is edited and recompiled on the laptop.
The executable application program is transferred to an internal non-volatile RAM disk in the SMC via the shared disk system. This program starts up automatically on reset so that the laptop is not normally necessary.