Rich I know this thread is a year old.. and I've been chatting with Chris (who is awesome btw). I wanted to let you know my experience with the 586.
I have a regular 586 and have absolutely no issues booting from the floppies or hard drive.. Any version 3 (3.0, 3.1, but no 3.2) and SDX or ADX utilities. So that system is fine. I could boot off floppies all day.
BUT on my 586T I cannot boot from ANY version of 3.0/3.1 or the ADX,SDX utilities. I've had some other posts on here where I was getting the **FAULT** issue when booting off ADX or SDX. I've spent a lot of time on this trying to figure out why this system will not boot Xenix floppies or the Utilities. I just want you to know your not going crazy and the system is probably fine.
So I get the same thing on the 586T where it appears to be loading and then just stops. I've tried v3.0, 3.1 and the utility disks. So I copied the main boards ROMS from the 586 as well as ones I have as bin files and that did not make a difference. On my regular 586 it uses Monitor 1.3 and that's the one I have no issues with so I figured maybe there was some sort of ROM lockout. I also double checked and compared all the jumpers in the machine. BTW on E11 you need to jump that if it is a 64K ROM and f it is a 32K the jumper needs to be removed. On my 586T it is running Monitor 2.1. So I did the ROM swap of all three on the main board, the hi, and lo and, the other one. With those ROMS it would pass powerup tests then just stop dead. So that didn't work.
I've also even tried swapping the HDD from the 586 in the 586T, nope does not work.
I'm not sure what is going on. I thought perhaps there was some sort of security Altos did so the machine could not be booted off Xenix. I thought maybe you had to hold the CTRL down or a function key or the break key. Nope didn't work. So I'm still dead in the water on the 586T with loading Xenix.. I do have the OS running on the 586T's original hard drive which is v3.0e. But I cannot update it or run any utilities at all. Someone knows the answer to this question out there..
I'd be curious to know if your machine had Monitor 2.1 as well. I think I even tried Monitor 2.2
Hope this is helpful.