KO4BB.com has disk images for the 4145A and 4145B, thanks to Wayne Knowles from NZ. I was able to make a 4145A boot disk using the image. The original disk for the 4145A is single-density, which is compatible with double-density disks. You can connect the original 4145A floppy drive to the PC, or use a single- or double-density floppy drive to make the boot disk. The 1.2MB high-density disk or floppy drive will not work.
