Subj : Re: what's classic now?
To   : Sean Dennis
From : Jeff Thiele
Date : Fri Jul 02 2021 06:25 pm

On 02 Jul 2021, Sean Dennis said the following...
 SD>  JT> I have, however, run into a small snag. The Mojo IO Shield uses all
 SD>  JT> of
 SD>  JT> the available IO pins, so there are none left for peripherals such as
 SD>  JT> an SD card or a serial port. I figure I have 4 options:
 SD> It's a "damned if you do, damned if you don't" situation.  Hopefully one
 SD> of the options, while not perfect, will work to get the problem fixed.

I think I'm going for the homemade panel, and have ordered parts.

The plus is that I can 3D-print the panel itself, with labels for everything,
and have plenty of pins left over. I can also have different-colored LEDs, to
group the switches into sets of 3 for a DECish look.

Now that the FPGA dev board is independent of the front panel, I've been
doing a lot of thinking about that, too.

My ultimate goal is to make this into a FidoNet-capable BBS, which in this
day and age implies BINKP. The Mojo board that I'm using has only 64K of RAM,
of which I'm using 48K as 32K 12-bit words. This should work great. My end
goal is to make a PDP8-based, FidoNet-capable BBS.

However, I also have the Alchitry Au+ board, with far more resources than the
Mojo, including 256K of RAM. That's enough to host multiple PDP-8 cores, and
a button could be added to the front panel to switch between which core is
connected to the front panel at any time, along with some LEDs to indicate
the "active" core. That would be extremely helpful if, for example, I wanted
one PDP-8 to handle BBS duties but another to fetch, process, and send BINKP
packets. I'll need to research how PDP-8s were networked back in the day, but
it seems like a serial connection would work as the bare minimum.

Jeff.

"For every complex problem there is an answer that is clear, simple, and
wrong." -- H. L. Mencken, who indeed was a racist thereby proving himself
right.
--- Mystic BBS v1.12 A46 2020/08/26 (Raspberry Pi/32)
 * Origin: Cold War Computing BBS (1:387/26)

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