There doesn't appear to be any disk i/o done after you see the prompt and press any key. It just cold starts the machine. I did try using a disk with DOS files on it. DOS.SYS boots like you would expect, and then the cartridge takes over and gives you the prompt, then does a cold start. That behaviour, combined with the clearing of parts of DOS memory, and the jumps into RAM, make me think that the disk that goes with this is a BOOT disk, that actually loads code into RAM.
I think you are correct. Again, I wondered if it was like the Educational System cartridge.
Perhaps they did this for copy protection... ??
Not in 1980. I can't think of any Atari program from that era with copy protection, but I could be wrong. But all they needed to to was show the sectors as unused in the block at 360 and they had copy protection that was good enough for the time.
If this proves to be the case, my guess would be for reasons of memory...perhaps to keep it in 16K? But that is only a guess. It may have just been a proof-of-concept thing that never got any further.
PS. I'm tempted to put an AUTORUN.SYS on the disk that loads code in at $1403, and puts $22 at $2295. The cartridge should then execute the code at $1403.
Good plan, I say go for it. I'm probably going to let you guys take it from here, I don't really have the time for this project now, nor the energy to deal with some of the users on this site.
The Personal Financial Management System software I posted above dates from 1981, I wanted to mention that. So that makes sense that if this was shelved in 1980, and the new one came out in '81, it fits.
The "Atari Accountant" is mentioned in the disk-version of the In-Store Demo, but not the cartridge version. So that also pegs all this work as being very early.
My guess is that the Accountant and whatever-this-was were shelved by 1980, and PFMS perhaps only sold for a year or so. Aside from The Atari Word Processor and Speed Reading, all of the neat "Binder" programs were dropped. That's sad because they are really classy; you don't see that kind of thing in the early PC's to this degree until the later boxed IBM manuals.
I don't know if we'll ever figure out what this was intended to be, but I'm going to stand by my guess that the label was a photo or trade-show prop for a project headed by the same person (or team, but at Atari a lot of the products were headed by one programmer), and then the shell was reused for this project, which eventually was rewritten into the PFMS software which was also shelved after a short life. And of course Accountant was later rewritten into The Bookkeeper, which although I love it, was also a flop.
So those are my thoughts on it.