[Coco] 16550 wasRe: RS232 paks

[Mark Marlette]

Bob,

Good information. Each system will vary a bit but 9600 to 115200 is a big jump, 57600 is to far as well. You will see the errors.

Flow is critical on the coco as the data can come in fast. NitrOS-9 has a lot going on to support the small buffer of the 6551. The 16550's buffer is large enough for the driver to grab the larger packets and keep up. Much more efficient. I would like even larger buffers but your choices are somewhat limited in the Super I/O chips from manufactures.

Regards,

Mark
Cloud-9


----- Original Message -----
From: "Bob Devries" <devries.bob at gmail.com>
To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
Sent: Thursday, March 5, 2009 7:36:21 PM GMT -06:00 US/Canada Central
Subject: Re: [Coco] 16550 wasRe:  RS232 paks

Of course, I have no idea exactly what the THROUGHPUT was in CPS with that 
setup.

--
Regards, Bob Devries, Dalby, Queensland, Australia

Isaiah 50:4 The sovereign Lord has given me
the capacity to be his spokesman,
so that I know how to help the weary.

website: http://www.home.gil.com.au/~bdevasl
my blog: http://bdevries.invigorated.org/

----- Original Message ----- 
From: "Tim Fadden" <t.fadden at cox.net>
To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
Sent: Friday, March 06, 2009 11:18 AM
Subject: Re: [Coco] 16550 wasRe: RS232 paks


> Hi Mark,
>
> This is my throughput with zmodem also using scsisys 1.1 hard drive with 
> modified os9, but not nitros. Using a Disto super II with a 4in1 card 
> serial port.  I do have a bootable Nitros9 floppy with the scsisys drivers 
> on them, so I could give it a shot with that, and let you know.
>>From my standpoint, the nitros9 floppy drivers lock up keyboard input, a
> feature I do not personally like.  I tend to type ahead a lot when doing 
> stuff.  Even on High-end Sun servers running solaris. :-)
>
> Tim
>
> Mark Marlette wrote:
>> Willard,
>>
>> Exactly my point. Zmodem by nature will re-xmit the loss but you can see 
>> that your effective baud rate goes in the tank.
>>
>> Was this Zmodem xfer saved to a hard disk or floppy?
>>
>> Regards,
>>
>> Mark
>> Cloud-9
>>
>>
>> ----- Original Message -----
>> From: "Willard Goosey" <goosey at virgo.sdc.org>
>> To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
>> Sent: Thursday, March 5, 2009 6:44:15 PM GMT -06:00 US/Canada Central
>> Subject: Re: [Coco] 16550 wasRe:  RS232 paks
>>
>> On Wed, Mar 04, 2009 at 08:12:44AM -0500, David Hazelton wrote:
>>
>>
>>> I have one built by Conect (IIRC)  Since when I bought it I only used 
>>> OS9, It worked great.  I did get better throughput then the RS-PAK.  I 
>>> did mostly Zmodem for file transfers, but I also logged in to VAX 
>>> machines and Unix based Machines at Work.
>>
>> I bet it did!  Zmodem likes uarts with fat FIFOs.  Under OS-9 with a
>> 6551, I couldn't ever get error-free zmodem downloads faster than
>> 4800. :-(
>>
>> Willard
>>
>
>
> --
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