TRS-80 Model 1 vs Model III disk/application compatibility question

Ethan Dicks ethan.dicks at
Tue Jan 27 14:02:00 CST 2009

On Tue, Jan 27, 2009 at 2:14 PM, Tony Duell <ard at> wrote:
>> Hi, all,
>> I was cleaning up around the house and wanted to stash a Model 3 on
>> the shelf out of the way....
>> I have diskettes, c. 1982, from a friend lying around, so I booted it
>> into TRSDOS 1.3.... What it does not do is run Zork or Enchanter.
>> I have original Zork I and Enchanter disks.  Booting up a backup of
>> the Zork disk gets me to a TRSDOS prompt.  I can take a DIR and see
>> the program and the data file there...
> As far as I rememebr, a Model 3 will not boot any Model 1 disk (or of
> course vice versa).

OK.  That makes sense and answers one question I had.

> So the fact that the disks boot to a TRS-DOS prompt implies they're M3 disks.

I wouldn't be surprised that all but one diskette I have is for the M3.

> I have Zork 1 for my Model 1. It was a self-booting disk, no TRS-DOS or
> similar. And it was copy-protected (nothing that SuperUtility couldn't
> manage :-)). So again, it sounds like you have a Model 3 version,

I have a hand-lettered "Zork Backup" disk that boots to TRS-DOS.  I also
have a commercial original that does not boot.  That one is probably for
the M1.

> Since the system will boot other disks and run other programs, I susepct
> either an unreadable sector on these games disks or something marginal in
> the disk drive or disk controller.

I would guess a bad sector on the game disks, since I have loaded over a dozen
programs from other disks successfully.  Since someone did ask, I did try to
boot drive 0 and run Zork from drive 1.  The only change was that the lights
had a slightly different cadence to them (since there are two drives), but it
looped endlessly and wordlessly all the same.

> Have you tried to make a ackup of Zork and/or Enchanter? If so, do the
> backups behave inthe same way?

I have not yet tried to make backups.  I have all the docs so backups should
be not difficult to do once I dig out a box of SSSD blanks from the back of the

One thing I'm not sure of with the Enchanter original is that since
it's marked "side 1"
and "side 2", but I don't have the box or the box insert, I can't tell
what platform it's for.
It _is_ marked "TRS-80", but I don't recall seeing a model number
mentioned on the
label.  The Zork game file is somewhere between about 70K-85K.  Enchanter is
almost certainly over 80K (I'd have to find a copy to check), so I guess I'm not
surprised to see that it overflows one side of a TRS-80 SSSD disk, but I am
unfamiliar with where they might have split things.  Does anyone else on the
list have TRS-80 versions of early Infocom titles?  The rest of my originals are
Amiga, PC, Mac, Atari ST, Atari 800, and C-64, so I have no experience
with TRS-80


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