Currently I am trying to get a UART board based on the NXP SCC82L92 chip working. However I found some little issues with the current design of the “backplane”:
I am missing the /IRQ and /NMI signals to the slots?
Did I forget to route them? Did I forget to take them into account when “drawing” the schematics?
I did already correct the schematics and have the signals routed in Kicad. Next step is to have a new run of boards made.
Also I am having trouble to get the SC28L92 to properly configure. I believe this has something to do with the way I wrote the ‘test” driver.
Currently I am going to migrate the current (working) 6551 based UART to slot 1 (have to reprogram the GALs for it), so I have better accessibility to the SC28L92 based prototype card with my scope and LA.
I hope to be able to publish schematics and sources in the near future, so others can also have a go at it.
I am also thinking about opening a Tindie store if there is enough interest. In the Tindie store I might sell DIY-kits and bare boards. This is (still) a faint idea.