[Coco] Re: CoCo needs?

[Torsten Dittel]

Mark: Some stupid hardware questions and thoughts (I guess many people
have figured this out before and it has been discussed a zillion times
here on the list, so please be patient with an ignorant old man ;-)):

I'm still wondering what it would need to produce a "new" floppy disk
controller. First my thoughts so far:

- The FDC IC has to be widely available and cheap and should be "command
set" compatible to the WD1772 (to allow programs which address it
directly). Is such a device available at all?

- Is there a way to use those 5.25" *HD* drives flying around at every
corner? I mean they should be able to *READ* reliably from a *DD* disk
and to *READ AND WRITE* to a *HD* disk, all in the CoCo's *DD* format
(*HD* might be an option for special drivers with OS-9)

- It should have features of an advanced controller with a sector buffer
and no HALT with special drivers and OS-9. Would this be compatible to
DEC-BASIC? Could the mode be changed by software? How did the ancient
no-HALTs work (wasn't that the Disto?)

Any comments?

Torsten