MS-DOS programs

[Revised Mar 02]

DOS programs under Windows

Windows can run DOS programs two ways;

- As a DOS Shell, concurrently with Windows programs. This is convenient to use since it is possible to use <tab> + <alt> to flick between the DOS program and 'RxOne'. But the Windows printer driver will handle the DOS printing, which can cause long delays in printing by the DOS program, and some DOS programs do not release the printer which can seriously interfere with printing under Windows, with either a long wait or messages such as 'Illegal function' or will crash out Windows, causing a 'Blue screen - Fatal error', in which case they must be run in DOS mode.

- In DOS Mode , Windows removes itself and just the one DOS task is running.

This is suitable for almost all DOS programs as normal DOS printing is used. The installer can set up an icon to switch to DOS mode and start the old dispensary program, and on exit to reload Windows. This is not as quick or convenient as a DOS shell (above), but is the only reliable way if the DOS program has to print .

The longer term solution is to change to Windows for all programs, including cash book, Wages etc. Windows programs are designed to co-exist.