UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Gemini 80-Bus System

JohnBHanson · 8th Dec 2019, 3:26 am

My guess would be that from what you say MFB1 was based on a GM829 floppy disk controller or a variant of. The upgrade was probably to GM849 controller with custom IC14 for copy protection.

I have a pdf for the gemini catalog No5. This does not list the GM849 controller but does
list the GM829 controller. It also lists the Multi Format System as a GM916 or GM921 depending on hard disk size of 5.4 or 16.5MByte. From what I have heard from you the MFB2 system is based on the GM849 modified floppy disk controller and has number GM925.

Maybe some of the documentation will through some light on the history. I am looking forward to reading the MFB manuals if you manage to scan them.

PS - Work is proceeding well on modifications to run the MFB system under xbeaver emulation.

8th Dec 2019, 3:26 am	#276
JohnBHanson Heptode Join Date: Aug 2009 Location: Worthing, Sussex, UK. Posts: 661	Re: Gemini 80-Bus System My guess would be that from what you say MFB1 was based on a GM829 floppy disk controller or a variant of. The upgrade was probably to GM849 controller with custom IC14 for copy protection. I have a pdf for the gemini catalog No5. This does not list the GM849 controller but does list the GM829 controller. It also lists the Multi Format System as a GM916 or GM921 depending on hard disk size of 5.4 or 16.5MByte. From what I have heard from you the MFB2 system is based on the GM849 modified floppy disk controller and has number GM925. Maybe some of the documentation will through some light on the history. I am looking forward to reading the MFB manuals if you manage to scan them. PS - Work is proceeding well on modifications to run the MFB system under xbeaver emulation.