[Coco] BIGGEST PROBLEM

[John Guin]

Can USB slow down to 9600 baud?  I know on the Arduino for the serial monitor (and serial connections in general) you set the speed to 9600 to 115K or so.

I could not find a minimum speed for USB documented anywhere, but saw that you could connect older 9600 baud modems via USB.  Seems like that would be do-able if this is the case.

John

-----Original Message-----
From: Coco [mailto:coco-bounces at maltedmedia.com] On Behalf Of Dave Philipsen
Sent: Monday, March 6, 2017 11:52 AM
To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
Subject: Re: [Coco] BIGGEST PROBLEM

I'm sure a 6809/6309 could handle USB.  If the 8051 can do it, the 6809 can do it.  However, I have heard that some of the 8051 variants have a built-in USB controller that offloads some of the work.  I don't believe you'll find a 6809 with this so you'd likely have to use a USB-controller chip (sort of like a fancy UART) to get the job done.

It's sort of like doing serial I/O with a real UART as opposed to the bit-banger port.  The bit-banger method pretty much requires all of the CPU's attention at higher bit rates while a real UART chip offloads the detailed work.


Dave


On 3/6/2017 12:16 PM, RETRO Innovations wrote:
> On 3/6/2017 10:03 AM, camillus gmail wrote:
>> Hi All,
>>
>> I was wondering, if a single 6809 or 6309 can handle USB protocol. If 
>> this could be done then a second cpu would be easy to imply in the 
>> exsisting coco's., and act as a dedicated USB controller ( does not 
>> have to be a 6809 but like to stay in the era )
>>
>> There are cpu/controllers with build in USB support.
>>
>>
>> - for the keyboard, this cpu can halt the main cpu to put characters 
>> that ist get from the usb board, directly in the characterbuffers of 
>> BASIC.
>>
>> - for mouse/ joystick I think something similar can be done.
>>
>>
>> I don't know I'm just a thinker...LOL But it would be not the first 
>> time someone made a big invention from someone else s idea's  ...lol
>>
>>
>> CB
>>
>
> I don't know that a 6309 can (for the performance reasons folks note 
> in other places), but there is a period-like device that has been 
> blessed with USB support:  the 8051.  You can do a search and there 
> are a host of 8051 variants that have built in USB.  Not sure about 
> HOST or OTG support, but I have to assume they have it.
>
>
> I know everyone on here is probably biased against Intel, but the 8051 
> line (which is no longer produced by Intel, as far as I know, but it 
> is their architecture) has led a very active life. Atmel and others 
> make 8051 variants and lots of stuff runs 8051 code.
>
>
> Jim
>


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