Re: ECB PropTerm

[yoda <yo...@r2d2.org>]

Why do we need another propIO which this is with a parallel port stuck in front of it?  PropIO works reliably under 6MHz and can be made reliable above that by just putting in a set/reset flipflop of the CS / enable connect to the wait.  I believe there are spare NAND gates on the board to do this but I have not had time to do that - seems it would be more productive to implement the solution on the current board and get a re spin then to make a whole new board.

On Tuesday, February 12, 2013 2:37:16 AM UTC-6, Sergey wrote:
> Hi,
>
> I uploaded the initial schematics for ECB PropTerm:
> http://n8vem-sbc.pbworks.com/w/file/63550295/ECB%20PropTerm%20-%20Schematic%20-%200.1.pdf
>
> Basically it is a ParPortProp together with an 8255 PPI and ECB
> interface attached.
>
> It provides simple and reliable terminal (and also SD card storage)
> capabilities to ECB systems.
>
> Perhaps schematic can be simplified a bit (I think 74LS241 buffers on
> EBC are redundant).
>
> I'd like to get any comments and suggestions...
>
> Thanks,
> Sergey