I'd like to put several PCBs in a panel with only one ISP connector routed to each MCU in parallel.
I hope that it will be no problem that many MCU's outputs will be connected together as it is intended that the output data will be always the same.
However I can not be sure that the programming device (STK500 in my case) will be electrically able to handle many devices (and how many in this case?) I think it is hopeless to try to find any specification as the programmers intended to be connected only to one MCU in a single time.
I did find a similar topic here, but Brian asked about parallel programming but I need to do it serially. And the question was related to relatively small amount of MCUs (3 in the picture) when I'd like to do this trick with a 20 or 30 devices!
So is there anything slept out of my sight? I could make an experiment with 2 or maybe 3 devices but I don't have enough boards to provide a full scale test, so probably someone did this? I'd like to have more PoVs before I will place a panel in the production.