[Coco] CoCo 3 MMU test for all

Roger Taylor operator at coco3.com
Sun Jan 20 11:12:48 EST 2008


At 08:42 AM 1/20/2008, you wrote:
>Hi Roger,
>
>It gives 121 on my Coco 3 with a 512K SIMM upgrade from Cloud-9.
>
>Guillaume

Ok, noted.  It kinda sucks that LOADM tries to verify back the byte 
just written and hopefully I can just patch the DOS during the LOADM 
and keep one version of the games I write.










>"Roger Taylor" <operator at coco3.com> wrote in
>message news:20080120143114.5D2A87D117 at qs281.pair.com...
> > Dudes and dudettes,
> >
> > There's a trick to creating super long LOADM'able programs on a CoCo 3 but
> > it relies on every CoCo 3 giving the same results of the following test:
> >
> > At the stock WIDTH 32 prompt, type:
> >
> > ?PEEK(65441)
> >
> > Won't you please type the above command on your real CoCo 3 only (not an
> > emulator), and post the results here?
> >
> > It *should* hopefully yield 57 which is an MMU block #, ofcourse.  If it
> > gives a reading of 11xxxxxx where the high two bits are set (or either of
> > the 2 high bits) then a separate special LOADMable program would have to
> > be created for that CoCo variation.  I could perhaps try to LOADM a patch
> > right into Disk BASIC that would ignore bad readbacks while loading, but
> > with all the types of DOSes out there, I doubt I will take that route.
> > The upper 2 bit statuses also might depend on the memory upgrade
> > installed, etc.
> >
> > I have already created a test copy of Jeweled which LOADMs the 32k
> > backdrop graphics into MMU 48-51 before loading the program itself.
> >
> > This is nothing new, but it *is* 2008 and my way of thinking is not like
> > it was in 1985 or even 2005.  In a 512k CoCo 3 using the extended LOADM
> > trick, huge extraordinary-for-a-CoCo 3 games with HQ sound effects and
> > dithered graphics could be loaded in up to the size of a floppy disk,
> > ofcourse.  A 128k-size .bin file containing the entire game contents?
> > I'll soon see.
> >
> >
> >
> >
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> >
>
>
>
>
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