[Coco] The Hobbit ported to 6809 (Dragon64 and coCo2 64k)

[Arthur Flexser]

Since one Basic ROM version can be replaced with another, no test based on
ROM contents would be totally reliable in distinguishing what model CoCo
you had.

I do seem to vaguely recall that some OS-9 thingie required a different
communications driver depending on whether you had a CoCo 1 or a CoCo 2.
So maybe some test based on that would be a way to tell the difference.

Or, I suppose you could look at the nameplate.

Art


On Sun, Aug 21, 2016 at 10:15 PM, Gene Heskett <gheskett at shentel.net> wrote:

> On Sunday 21 August 2016 21:11:37 Barry Nelson wrote:
>
> > Does anyone know a way of telling a CoCo 2 from a CoCo 1?
> >
> One possibility might be in the first few bytes of the basic rom at
> $A000. I had an old grey ghost first, (still have 2 or 3) and I fixed
> Jake Commanders little editor to live in high ram so it din't borrow a
> kilobyte of basic's memory.
>
> But when I got my first coco2, it didn't run very well, lots of lag.  It
> seems that they had moved the keyboard scan routine a few bytes, and
> Jakes code was skipping the vector lookup in the first few bytes of the
> rom and was still jumping to the original address.  So I looked up the
> vector address and changed jakes code to use the vector address by
> getting it from the rom.  After that it worked great on either a coco or
> a coco2. So someplace in the first 32 bytes of the basic rom, there is a
> different vector integer for the keyboard polling routine.
>
> But I'll defer to Art as to whether or not this is a good indicator of a
> coco1 or a coco2. Since most if not all the white/cream coco2's shiped
> with basic-1.1 it might work quite well.
>
> That vectors address is mentioned in the basic book they came with IIRC.
>
> Strange, the things I can remember from 30 years ago, but I'd have to
> hobble to the basement and find one of those books before I could quote
> it here.  Bad knee, worse back, I'm wearing out. Lots of miles on this
> soon to be 82 yo carcass.
>
> Stay well & take care everybody.
>
> > > Pere psergm at gmail.com
> > > Sun Aug 21 18:54:38 EDT 2016
> > >
> > > Hi Brett,
> > > thanks a lot for that pointer.
> > > I have found that $FFFF contains $1B on a CoCo3, $B4 for a
> > > Dragon/Tano and $27 on a CoCo2
> > > Probably this could be a good 'signature' to look for ...
> > > I will try to add the changes proposed by Art and this one tomorrow
> > > I'd love to have a single binary working on the Tano/Dragon64, CoCo2
> > > and CoCo3
> > > despite the RAM constraints that suffers this project.
> > >
> > > cheers
> > > pere
>
>
> Cheers, Gene Heskett
> --
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> -Ed Howdershelt (Author)
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