[Coco] CoCo3 PIA?

[Robert Gault]

Mark Marlette wrote:
> Does someone know if IC5, LSC part number is a TTL or CMOS device?
> 
> I'm working on on interface device and I need to make sure that I  
> don't have a I/O conflict.
> 
> Since it is on the keyboard port it appears that a zero represents a  
> key press. So the A side must be inputs and the B side are the drives  
> of IC5.
> 
> With that said then if no key is pressed(N.O. contact configuration)  
> the A side input of the PIA must be pulled high, thus indicating no key.
> 
> This is a weird part number and I'm not exactly sure what is different  
> in this part than a 6821.
> 
> Someone know more on this device????
> 
> TIA,
> 
> Mark
> 
> 
> 
> 
IC5 is listed as LSC81001P or SILS81001P and is N-MOS. I think it is 
also a 68B22.

IC4, the other PIA is also N-MOS and has many sources: MC68B21P, 
MB8874HM-G, HD68B21P.

I don't have a data sheet for the MC68B22 but believe it is the same as 
the MC68B21 but with more robust outputs.