On Sep 22, 2023, at 3:07 PM, Chuck Guzis via cctalk
<cctalk(a)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.
        paul