RL02 version of UNIX6?

simH did not change the size of the disk image. By default, simH will automatically detect the type of disk on a particular controller (e.g. RL01/RL02, RK06/RK07) based on the size of the disk image. When I attached the image and did a?sh rl0? it showed up as an RL02 - those extra few bytes made the difference. The RSX distribution kit I have is probably from a different source. Later testing showed that I could copy the baseline disk to an RL02 using standalone BRU but I was unable to do the copy using standalone DSC (an earlier backup program). I just checked the current simH source and, if autosize is enabled, it treats any image file larger than an RL01 as an RL02. If you turn off autosizing and set the drive to RL01, it will always consider it an RL01, regardless of the actual size. Any attempt to read/write past 5MB will return an error. John.