[Coco] Re: [Color Computer] mystery chip on COCO2 XC80652P

[jdaggett at gate.net]

Bruce

Neither port is open collector.

Both Port A and Porrt B are open Drain. Maximum pullup voltage is 
18 VDC. Each port pin must have an external pullup resistor. Not 
sure but the sink and source currents are not very high. maybe one 
TTL level ~2 ma.

james


On 6 Mar 2004 at 22:20, Bruce Calkins wrote:

To:             	<ColorComputer at yahoogroups.com>
From:           	"Bruce Calkins" <bcalkins at disaster-
relief.net>
Date sent:      	Sat, 6 Mar 2004 22:20:22 -0500
Copies to:      	Subject:        	[Coco] Re: [Color Computer] 
mystery chip on COCO2 XC80652P
Send reply to:  	ColorComputer at yahoogroups.com,
	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>

> Without looking it up I'd say it is a 6822..  It is closely related to
> the 6821.  I forget which one is open a collector and which one is
> closed  If I understand correctly, the main difference is the current
> direction.  It is used for the keyboard interface.
> 
> Bruce W.
> 
> 
> 
> All-
> 
> I have a coco2 wih 64K that is built on  a PCB with number 20261058.
> 
> There is a large 40 pin IC that I cannot identify-- it is labelled
> XC80652P.
> 
> Can anyone help identify this?
> 
> Thanks, Steve
> 
> 
> 
> Brought to you by the 6809, the 6803 and their cousins! 
> Yahoo! Groups Links
> 
> <*> To visit your group on the web, go to:
>      http://groups.yahoo.com/group/ColorComputer/
> 
> <*> To unsubscribe from this group, send an email to:
>      ColorComputer-unsubscribe at yahoogroups.com
> 
> <*> Your use of Yahoo! Groups is subject to:
>      http://docs.yahoo.com/info/terms/
> 
> 
> 
> -- 
> Coco mailing list
> Coco at maltedmedia.com
> http://five.pairlist.net/mailman/listinfo/coco