Incidentally, I have an IBM System/23 for which I have not yet procured any software. In particular, I could use whatever utility software that's necessary to format data disks. I haven't found any online sources of disk images for this system yet.
http://www.nf6x.net/2014/08/ibm-system23-datamaster/ http://www.nf6x.net/2014/09/ibm-5322-system23-datamaster-internals/ -- Mark J. Blair, NF6X <n...@nf6x.net> http://www.nf6x.net/