22 hours ago, BruceMcF said:
Yes, I was a little disappointed it did not show up here, but what I really want to show up here is a detailed description of the new expansion card format, and that post did not have many technical details.
At a glance and squinting at the silkscreen above and comparing it to a published signal breakout from the prior (proto2) 50 pin slot, it looks like:
'BUS_L' and 'BUS_R" are labeled on the old diagram but not here; however the silkscreen above shows AUDIO_? and AUDIO_? (? is because I can't see the suffix). It could be these are the same signals... but I don't know. VPB - (vector pull) has been added. NMIB - (Non Maskable Interrupt) has been added. Seven (7) more (by my count) GND paths have been added. A second 3.3v has been added. Virtually all signal locations have been rearranged.
From where I sit: NMI on the add-on card slot is good for obvious reasons. Probably also that vector pull signal. If memory serves, 'vector pull' is sort of a 'look at me to see if the processor is acting on an interrupt vector' kind of signal. I have no idea how that all works in practice but its probably worthwhile addition.