There are a number of other old patient administration systems (all UNIX based, mostly SunOS but OpenVMS as well, all delivered by terminal session) that are in use currently and hospitals that use them are being migrated to the new single system but it's a slow process as the new system does more than just patient administration, it replaces a number of other old systems as well.
So that it's MS-DOS based is just plain wrong.
I don't want to get into the licensing issues with Working Systems.
How do I know this? I work for the department..
This is why the rest of the world uses ICD-10 coding.
Riches cover a multitude of woes. -- Menander