[Coco] V.PAGE 46551 and 46552 drivers

L. Curtis Boyle curtisboyle at sasktel.net
Mon Jul 21 20:08:22 EDT 2008


On Mon, 21 Jul 2008 15:46:42 -0600, George Ramsower  
<georgeramsower at gmail.com> wrote:

> ----- Original Message ----- From: "L. Curtis Boyle"  
> <curtisboyle at sasktel.net>
>
>>>
>>     That may be true for disk controllers, but RS-232 does allow  
>> multiple cards (the Comm-4 board from Alpha technologies had 4 ports,  
>> as an example). The device descriptor determines it by the address of  
>> the card, and each get's their own buffer (especially if using SACIA  
>> for 6551 based ports, and DACIA for 6552 based ports). When we used to  
>> run the Coco 3/Nitros9 system here at work, we had 3 parallel ports,  
>> and 8 serial ports (4 6551, 4 6552 (2 ports per chip on the latter),  
>> and we drove 8 ADM terminals from those.
>>
>
>  Are the drivers and descriptors available for these chips? I've been  
> wanting to build a new board for my coco using one of these chips to  
> replace the 6551 chips I'm using now.
>  My current board has three of the 6551 chips and from what I hear, the  
> 46551 and 46552 are superior.
>  I use stock OS-9 L2 on a 512K CC3.
>
> Thanks,
>
> George

Both SACIA and DACIA were part of Nitros9 at least up until 2.01, so I  
assume the source should be with the current NitrOS9 project. Both were  
originally done by Bruce Isted, and I don't recall too many changes being  
done afterwards by any of us on the NitrOS9 team.
Also, what I meant with "4 6551, 4 6552" is that we had 4 ports running  
off of 6551 chips (4 chips; 1 port per chip), and 4 running off of 6552  
chips (2 chips, 2 ports per chip, with up to 38.4kbaud and none of the  
nasty bugs with date/DTR that the 6551's had). The 6552 was used in the  
TC-9, and the Eliminator disk/hard drive/clock/parallel port/dual serial  
port controller that Frank Hogg sold for the Coco. That was an excellent  
controller, except for no RS-DOS compatibility, and it's use of obscure  
(even at the time) WD-1002-05 controller cards (hope I got that last  
number right; going from foggy memory here).


-- 
L. Curtis Boyle



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