[Coco] Clud9 512K upgrade for the Coco3

Arthur Flexser flexser at fiu.edu
Thu Jan 29 18:18:18 EST 2015


That's too simple to work, Allen.  The problem is that $1FFFF ghosts to
$7FFFF (along with $3FFFF and $5FFFF), so even a 128K CoCo 3 would pass
that test.

You have to do something like poke $1FFFF and verify that the contents of
$7FFFF have NOT changed to see if 512K is there.

Art

On Thu, Jan 29, 2015 at 4:04 PM, Allen Huffman <alsplace at pobox.com> wrote:

> > On Jan 29, 2015, at 2:14 PM, Tony Cappellini <cappy2112 at gmail.com>
> wrote:
> >
> > Is the Triad 512K upgrade for the Coco 3 fully accessible under Nitros9?
>
> All 512K upgrades are. Any that went beyond that (1MB, 2MB) required
> software updates specifically for the non-standard implementation.
>
> > Are there any games or other programs written that require the 512k
> upgrade?
>
> Tons. Most of the good 3rd party stuff requires 512K. The Donkey Kong
> conversion even does.
>
> > I don't expect that this can be fully accessed from Basic. How do I
> verify
> > that the system sees the full 512k?
>
> There are 512K test programs which is the best way.
>
> From BASIC, you get LPOKE and LPEEK to put bytes anywhere in the 512K
> memory map. By using other POKEs, you can bank in and our 8K blocks to use,
> BUT stock BASIC doesn't do anything with it directly -- you still get the
> same amount of RAM for BASIC as a 32K CoCo had.
>
> I have not tried this, but it might be as simple as seeing if you can set
> something in the 512K space:
>
> PRINT LPEEK(&H7FFFF)
> LPOKE &H7FFFF,42
> PRINT LPEEK(&H7FFFF)
>
> Not sure that that address is correct, but if you can LPOKE a value in the
> upper memory, and read it back, that would show the memory was there. That
> said, the next step could be doing that for ALL the upper memory -- though
> that kind of test would take forever to run in BASIC. Maybe checking a byte
> in each 8K block would be good.
>
>         -- A
>
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