[cctalk] Ampex and the DG Compatible Market

Although I knew that Ampex was a supplier of Multibus non-volatile RAM boards (MC-8080 and MCM-8086) - Memory Products Division - I didn't realize that they had competed for a while in the DG-compatible market alongside companies like Digidyne, Fairchild, Bytronix, and SCI Systems (according to court documents and the trade press). Can anyone shed light on what they offered and when? And perhaps why? Thank you, paul