Hi Ian. This work you are doing on the FW is incredible. Many thanks for your efforts, and to every one else for their contibutions.
I plan on doing the following to your version once you are "done" with the non-hardware mod version..
1: Convert to I2C LCD, free up 6 digital I/O.
Move keyer jack to D8 for DIT and D9 for DAH, should work well as there is a GND connection between the 2 on the OLD LCD header (pin 4,5,6)
Move PPT to D10 (pin 11)
Move Button to D11 (pin 12 and 16 for GND)
Move ENC to D12/13 (pin 13,14 and 16 for GND)
Also gives easy access to +5v on pins 2 and 15 for my I2C TPA2016 AGC and SSM2167 MIC Amp.
I2C breakout as per Jim Sheldon's method, I need 2 of each for AGC (+3.3v) and LCD.
Now what to do with all those free Analog ports?
A7: S-Meter. (vk3YE AGC with out the AGC part, only the SIG meter...)
A6: SWR bridge rev (Kitsandparts.com)
A3: SWR bridge fwd (Kitsandparts.com)
A2: Array of buttons (via different resistors) for direct access to: Band up/down, RIT, VFO A/B...
A1: Potentiometer to for ACG control (via the I2C AGC module)
A0: ...
Hope to get the FW to display s-meter on RX and the SWR and PWR on TX on the top line.
Thanks again.
Nick VK4PP