[Coco] Clud9 512K upgrade for the Coco3

[Allen Huffman]

> 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