Hi Sam, today I busy for find old disk drive and 1.44 disks. Eventually by many times test, I found a good driver and a 1.44 disk. Install Msdos6.22 and format the disk , then run your file. It work make me come back to old time. after reload the 8711a firmware, the machine can run and check the other units. This challenge work is too excite,I will continue this challenge, thanks Sam. 73!