An update for the list, so it gets stored for the next person. I have achieved success. The link issue was as simple as changing the file extension on the M80 link file from .REL to .ERL. As soon as that was done, everything linked just fine, and the code was even able to be called from pascal. the final link command was something as simple as LINKMT FORMAT5,FORM5,PASLIB/S And the 3.5 inch disks, they just work. The system is a Pulsar Series 6000 'Little Big Board', which is a Z80 based STD card. Originally, I built it with 8 inch disks in about 1984, and about 12 years ago, I migrated to 5.25 inch drives using the Mitsubishi 4854 drives. They were hardware compatible, spinning at 300rpm. Of course I had to make a 50 pin to 34 pin adapter, but that was not hard. The complexities associated with moving from 5.25 inch to 3.5 inch were the DC/Ready issue, which was well understood, and having to change the formatter so it would keep writing nulls for that last 20% of the disk, due to the speed difference (360 vs 300rpm). Once that was dealt with, everything just works! Things to do on a rainy day: 1) figure out how to write an extra sector or two to the 'end' of the disk to take advantage of the extra space (This will involve CP/M bios changes) 2) Increase the number of tracks from 77 to 80 - also involving bios changes. But in the meantime, I finally have a CP/M system that is using 3.5 inch media. It is understood that there is no way that the media can be used in another system.... As my sister says.... "How 80's - When are you going to put Compact Flash on that thing?" :-) Doug