help!!!! upload sketches to many mini pro's at the same time

I'm not trying to change the bootloader I only want to upload sketches to many mini pro's at the same time. Has anyone a solution for this? I'm designing a new product and using the arduino to control it. However, I need to be able to reprogram them (at least 30 at a time) at once. Any advise is greatly appreciated.

Write some custom code to do it, has to ignore any responses back from the chips.
Is being discussed in another thread also.

Didn’t you already post this question before? I think they answered you best they can without know more about what your circuit does. There are many variables to programming and without know more details we can only guess at it.

So you have a product. It is using 30 pro minis. You want to program it “in circuit”. You only want one port to program all 30 pro minis. What kind of reliability do you need? Is this a non-critical application so if a chip fails to program correctly it will not cause a catastrophic failure or injure someone? Why must you program all 30 at once? Is due to operational issues or just convenience?

Note ISP programming is not just for burning bootloaders. It can be used for uploading sketches too. Programming “in circuit” requires the use of special ISP pins, MOSI, MISO, SCK, and RESET. Are you using these pins for other functions? If so you will need to alter your circuit for multiplexing pin usage.

Bottom line is we need more details of what you are trying to accomplish.