Unpopulated headers on TRS-80 Model II Revised Floppy Disk Controller.

[bladamson]

Howdy folks. Figured I'd make a new thread for this since it's such a specific question.

I appear to have the revised version of the Model II floppy controller.



It has two different interfaces, internal and external, so the terminator plug is not needed on the external port. Or something.

As you can see, it has two unpopulated 34-pin headers. Presumably one for the internal interface and one for the external interface.

Rather than fooling around making an adapter to plug the floppy emulator into the 50 pin 8" drive connector, can I just solder headers onto those empty spots and hook the thing to up to that?

That's probably a dumb question, heh. But I just don't want to fry anything!

 

[Hans01]

The unpopulated connectors are made for 2 internal 5.25 and 8 inch drives.
You can restore them with 34 pin and 50 pin pinheaders.
These functions are jumper selected.
In the basic configuration the flatcable connector is set for external drives (jumper selectable)
You need special drivers for the 5.25 drives.
See the options in the table.

View attachment jumpers.doc

 

[bladamson]

Hmmmm, alright cool. I guess I'll try it and see what happens. I mean, as far as emulating an 8" disk on the internal 34-pin connector using a gotek with flashfloppy firmware. It sounds like in the worst-case it just won't work, and I'm not likely to let any magic smoke out.

 

[pski]

One downside of using that 34pin connector is that you won't be able to use 2 sided disks since the 8" interface requires that 2sided signal. Adapters like the fd50to34 provide that feature via a jumper. You could rig up a 2 sided jumper to the 50pin connector, I guess, but then why not just use the adapter at that point.