RC80 PROPIO V2.0

CAUTION! Very preliminary - WORK IN PROGRESS - UNDER CONSTRUCTION

UPDATE: Received feedback after prototype built. Fixed RC80 connector and 74LS06 schematic/pcb footprint. Corrected U6 74LS74 VDD vs +5V issue in library - created user part.

Objective: Migrate the PropIO 2.01 board to RC2014 environment utilizing a "bus compatible" RC80 bus.

The baseline "parent" design and the relevant Propellor Firmware can be found here:
https://www.retrobrewcomputers.org/doku.php?id=boards:ecb:propio:start

And the baseline "parent" design derives software support from here:
https://www.retrobrewcomputers.org/doku.php?id=software:firmwareos:romwbw:start

It is expected that this board design may be 100% compatible with the RomWBW support
already established for the "parent" design.

Many thanks to the original designers!

2020/07/11 - created first attempt at routing the board. It is crowded 100mm x 75mm so far. Standard RC2014 is about 100 x 49. We are not constrained to that profile.
*Have replaced 74682 with 74688. Added USR RC80 pin support for Z280 support using additional address card.