[Coco] (No subject)

[Arthur Flexser]

That's definitely not what I was talking about.

A scan for the end of memory SHOULD check one byte of ROM, discover it is
not RAM, and so the byte before that would be the end of RAM.  (I assume
that Super Extended Basic would patch in going to ROM mode first, so that
the test would work for a CoCo 3.)

Art

On Thu, Jul 14, 2022 at 1:38 AM Allen Huffman via Coco <coco at maltedmedia.com>
wrote:

> On Jul 13, 2022, at 11:35 PM, Arthur Flexser via Coco <
> coco at maltedmedia.com> wrote:
> >
> > Allen, I believe you're wrong about Microsoft having made a one-byte
> memory
> > mistake that Microware corrected for the CoCo 3.  My memory is a little
> > vague on this, but I have a recollection that the CoCo 1/2 actually needs
> > that extra byte, but the CoCo 3 doesn't because Basic is running out of
> RAM
> > on the CoCo 3.
>
> I found it at LA084 in Color BASIC Unravled.
>
> There is a RAM scan to find the end of memory. X points somewhere and it
> increments by 1, but when it does the test, it checked 2,X so when it gets
> to 32766 it’s trying to check ROM and the test ends there. On a RAM system
> it can continue to check.
>
> It kinda looks like a bug since it increments by 1 and maybe could have
> just checked that byte or one after it.
>
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