The AT6xxx controller products required Operating System file downloads after every power up of the computer (these were ISA bus based controller cards). The final operating system revision of each of the cards are included here for download. The attached zip files also include the old programming examples in various programming languages for reference.
(The AT6n00 includes the AT6200, AT6400 and the OEMAT6400 products)
Note - refer to this alternate FAQ posting to discern revision compatibility before downloading a later revision. If you card is not compatibility with the revisions posted here, contact technical support at 1-800-358-9070 for older revisions of these OS files.