[Coco] How about a new FDD Controller?

jdaggett at gate.net jdaggett at gate.net
Sat Nov 6 09:58:16 EST 2004


Jim

A hardware upgrade for the WD1773/1793 chip used would be to 
use the WD2793. There would be no software cahnges and the 
WD2973 is comparable to the uPD765 and the Intel Floppy 
controller. 

The WD2973 is still findable, BG Micro comes to mind as having 
them. This would require an new PCB Layout and would not be that 
difficult. 

The FLex group already has a controller card that is on the SS30 
bus that uses a CPLD and the WD2973. One could take the chips 
and relayout the buss interface so that it fits the Coco Expansion 
Buss and all is well.

james

On 5 Nov 2004 at 14:05, Jim Cox wrote:

From:           	"Jim Cox" <jimcox at miba51.com>
To:             	<coco at maltedmedia.com>
Date sent:      	Fri, 05 Nov 2004 14:05:00 -0800
Subject:        	[Coco] How about a new FDD Controller?
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> Besides time, money, and interest, what are the major 
> obstacles to someome building a new Floppy Controller for 
> the CoCo?
> 
>  From what I understand, it's primarily just finding or 
> making a replacement for the Western Digital chip.  If 
> people are attempting to make and PFGA version of the 6X09 
> and the GIME, shouldn't the Western Digital chip be 
> easier?
> 
> Also, if someone were to build a new controller, would it 
> be possible to design it in such a way that 1.2M 5.25" 
> drives could be used to replace the older 360K 5.25" 
> drives?  I know there are actually differences that 
> prevent using the 1.2M drives with current controllers, 
> but could there be some "tweaks" in the firmware of the 
> controller to get around this?
> 
> DriveWire is nice, but it only works for NitrOS, and while 
> I plan to use it for that, I would also like to work with 
> DECB  stuff too.
> 
> Isn't someone developing a USB controller for the CoCo? 
>  If so, could one of those USB 3.5" floppies be used with 
> it?
> 
> Jim Cox
> 
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