Re: Turbo232 UART Cart HDL

From: Jim Brain <>
Date: Thu, 12 Dec 2013 13:30:04 -0600
Message-ID: <>
On 12/12/2013 12:22 PM, Mike Naberezny wrote:
> On 12/12/13, 9:31 AM, wrote:
>> The discussion caused me to ponder options.
>> 6551s are becoming hard to find (yes, WDC now makes 6551, but it's 
>> not cheap)
> Jameco has stocked the 6551 for years. 
I had not checked there lately.  I thought they were reducing their 65XX 
stock, but if it's still there, that's good.
> I don't know what you consider cheap but they have both the 6551 and 
> W65C51N for less than USD $5/ea with discounts for quantities of 10 or 
> more.
$5 is not "expensive" in absolute terms, but for $5.00 in singles, I can 
obtain a AVR ATMEGA164, which provides a whole host of features.  in 
ARM, I can get a Cortex M3 running at 50MHz with 128kB of ROM and 16kB 
of RAM, coupled with a huge host of peripherals onboard.  So, in 
relative terms, I can offer a lot of functionality (dual or quad uarts, 
huge FIFOs, onboard tcpser functionality, etc. at the same cost.

But, the fact that 6551s are still available means I could start with a 
simple solution and work my way to something larger.  Mainly, I didn't 
want to create a project that made people scratch their heads and say, 
"Gee, Jim, I'm glad you put plans out there for a PCB and CPLD 
equations, but since I can't easily source the 6551, you've just teased 
me with something I can't make or use".


Jim Brain

       Message was sent through the cbm-hackers mailing list
Received on 2013-12-12 20:00:04

Archive generated by hypermail 2.2.0.