Why .scp file sizes were increased by 1KB when updating FW1.1 to FW1.6?

[Hanzugam]

Hi

I have been reading my Amiga disks as .adf and .scp files. As you know .adf is always 880KB but .scp size is bigger and varies, but when you have same content on two discs and their .scp size is indentical you can be sure they are indentical copies of each others.

Today I decided to update Greaseweazle F1 Plus FW version 1.1 to FW version 1.6. After reading two same disks to .scp again with FW 1.6 I noticed they suddenly very 1KB bigger than the ones I had made earlier with FW 1.1. I believe I have not changed any settings and I have used same FDD for all of them.

What can be assumed to cause created .scp sizes to be 1KB bigger?

[Hanzugam]

After re-reading different third disk for a third time. It was again exact same size, so adding 1KB seem to be random and not systematic.