[Coco] CoCo 3 MMU test for all

[Bob Devries]

Hi, Roger,

My Aussie PAL coco3 (with 1MB ram, BTW) yields 121 ($79 %01111001).

--
Regards, Bob Devries, Dalby, Queensland, Australia

Isaiah 50:4 The sovereign Lord has given me
the capacity to be his spokesman,
so that I know how to help the weary.

website: http://www.home.gil.com.au/~bdevasl
my blog: http://bdevries.invigorated.org/

----- Original Message ----- 
From: "Roger Taylor" <operator at coco3.com>
To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
Sent: Monday, January 21, 2008 12:31 AM
Subject: [Coco] CoCo 3 MMU test for all


> 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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