It could run LDOS TRS-80 software three times faster. Nevertheless numerous internal differences made it incompatible as far as hardware was concerned: serial and parallel ports, disk interface and no tape connector.
The system also ran CP/M operating system. the early versions were
shipped with 2.2 version, next ones with version 3. It could accept any 5" or 8" disk units of any capacity, including the new and rare (at that time) Sony 3.5" units.
More information by Clarence Perry:
I purchased a Max 80 in 83 with LDOS. The Max 80 did not have a boot rom like the TRS80. It was basically a CPM machine which didn't require much in ROM and loaded everything from disk.
LDOS for the MAX 80 had a version of the model 1 basic rom as a disk file which had to be loaded into low memory during boot. My hat is off to the guys who wrote & documented LDOS because it still stands as one of the finest pieces of computer documentation I have seen.
I did some assembler work on the Max80. I posted a task switcher on Compuserve that switched between different LDOS sessions running different applications with a key combination. The source was there also. It was pretty easy to do due to the memory arrangement. That was also enough of a taste to decide I never again wanted to do assembler.
Back in the early 80''s, I traded a S/W 357 revolver for my jewel. It had 4-8", 4-5", a 3.5", and lastly a 3 mb Hardrive. It came with a GE Line Impact Printer. I loved it, and it was fun to learn Basic, CPM and some CPM3 on it. The Amber monitor was eaiser to read for extended time and there is nothing negative I can say about the unit. It worked perfect, was easy to fix, reprogram and I hope the fellah I sold it to, got as much use out of it as I did. That is when I went to MS-DOS permanently. I have very fond memories of those times.