[Coco] Re: CoCo needs?

[jdaggett at gate.net]

Torsten

The WD 2793 would be the ideal chip to design a round, but it to is becoming rare. 
These too are drying up in the surplus market. It is software compatible with the 
1793 and is a single 5 volt part. It does not require the two external support chips 
that the 1793 uses. This would be the painless way to go.

Any other chip may require software changes that tends to obsolete many disk 
software already written. Not a good situation. 

james


On 8 Mar 2005 at 21:29, Torsten Dittel wrote:

To:             	coco at maltedmedia.com
From:           	Torsten Dittel <Torsten at Dittel.info>
Date sent:      	Tue, 08 Mar 2005 21:29:51 +0100
Subject:        	[Coco] Re: CoCo needs?
Send reply to:  	CoCoList for Color Computer Enthusiasts 
<coco at maltedmedia.com>
	<mailto:coco-
request at maltedmedia.com?subject=unsubscribe>
	<mailto:coco-
request at maltedmedia.com?subject=subscribe>

> 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
> 
> 
> -- 
> Coco mailing list
> Coco at maltedmedia.com
> http://five.pairlist.net/mailman/listinfo/coco