LaF0rge, 3 months ago

edited circuit board photographs of each #Siemens EWSD #ISDN switch circuit board in our collection now in the #osmocom #retronetworking wiki below https://osmocom.org/projects/retronetworking/wiki/EWSD_Components - now we "just" need to add description texts and metadata like part numbers, cross-references, etc.

mnt, 3 months ago

@LaF0rge wow, 4 USARTs but no CPU? looks like d/a trickery judging by the precision resistor network below

LaF0rge, 3 months ago

@mnt an EWSD telephone exchange contains hundreds of boards in dozens of component carries and >= 3 racks full of component carriers. Not every board needs to contain a CPU, though many do.

ve7fim, 3 months ago

@LaF0rge

I just love all those vias that double as test pads on that last board... The good old days of slower clock speeds.