[Coco] 16550 wasRe: RS232 paks

Gene Heskett gene.heskett at verizon.net
Wed Mar 4 10:53:07 EST 2009

On Wednesday 04 March 2009, David Hazelton wrote:
>Willard Goosey wrote:
>> On Wed, Mar 04, 2009 at 08:53:06AM +1100, Mark McDougall wrote:
>>> I also believe that at least one person has "gone 16550" to use his
>>> words??? Is that the case? Are there many here that are using 16550, and
>>> what software supports it?
>> There have been one or two projects to build a 16550 serial card.
>> >From what I understand, they have floundered not on the hardware
>> issues, but on software issues. :-(
>> Writing an OS-9 driver is one thing, but (I believe) the 16550 can't
>> really pretend to be a 6551, and this breaks *every* BASIC terminal
>> program ever written...
>> Willard
>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.
Since the 16550 needs a 16 wide group of register addresses, which would 
displace 4 regular packs from the coco's address space, I wonder how that was 
handled?  I could see it being done with a 2 byte write or read sequence where 
the first write sets the register address, the next read or write then sets or 
gets that data. If the IRQ source register address wasn't subject to that, I 
could see it being done in the usual coco 4 byte wide address space, of course 
with its own driver.

Was the Conect driver ever dissed and made part of the nitros9 package?

Cheers, Gene
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
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