[Coco] DW and 6551

Stephen H. Fischer SFischer1 at Mindspring.com
Tue Feb 10 23:26:11 EST 2015


It has been ~ 35 years since that was talked about.

http://mirrors.apple2.org.za/apple.cabi.net/FAQs.and.INFO/CPUandMore/turboasb.txt
-------------------------------------
Why do you need a replacement chip? Simple, the 6551 chip that is on most
Serial Interface cards has a design flaw in it that causes it to lose a
character every time the CTS line is switched.
 
In most cases, this is not a problem. However, with modem speeds 
continuing to
rise, people have started using Hardware Handshaking cables to connect their
computers to their modems to achieve even higher speeds. This is where the
problem lies.

-------------------------------------

SHF

----- Original Message ----- 
From: "RETRO Innovations" <go4retro at go4retro.com>
To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
Sent: Tuesday, February 10, 2015 8:00 PM
Subject: Re: [Coco] DW and 6551


> On 2/10/2015 9:26 PM, Stephen H. Fischer wrote:
>> And there is the 6551 flaw if I remember correctly voids the entire idea of using it.
> What flaw is that?  The CBM folks use 6551s all the time with no issues.
> 
> JIm
> 



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