On Sat, Sep 23, 2023, 12:31 PM Paul Koning via cctalk <cctalk@classiccmp.org>
wrote:
>
>
> > On Sep 22, 2023, at 3:07 PM, Chuck Guzis via cctalk <
> cctalk@classiccmp.org> wrote:
> >
> > On 9/22/23 11:34, emanuel stiebler via cctalk wrote:
> >
> >> There are still some 84pin chips out there(Altera & Xilinx). Sometimes
> >> they are pulls, or some 5V tolerant xilinx xc95xxxxl
> >
> > I still have a few 84 pin PLCC XC95108 5V CPLDs Originally, I did a
> > tape controller design with one before Xilinx discontinued them. I
> > figured that using a discontinued part was not the way forward, so I
> > dropped the project. Xilinx did/does have its ISE design suite, which
> > is fairly easy to use.
> >
> > Eventually, it turned out that using a reasonably fast MCU with 5V
> > tolerant I/O worked just as well and avoided the "mystery in a chip" of
> > a CPLD.
>
> I used an Arduino Feather that way, for my PS-2 to LK201 converter. And
> while not 5V tolerant, a Raspberry Pico is a particularly powerful and
> cheap option; one of my projects could run DDCMP at 10 Mb/s including the
> "integral modem" compatible signaling.
>
> As I mentioned, 5V tolerant inputs can, at least for not too high speeds,
> be done simply by resistive voltage dividers.
>
What's too fast in absolute terms?
Warner
paul
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>
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