[Coco] Programs larger than 32K?

[Robert Gault]

You could have a loader program that set up ALL RAM mode, copied the RAM from 0-$E00 to $C000-$CE00 
and then switched back to RAM/ROM. Then any software that switched banks would have all the Basic 
variables in each bank.

Robert

Arthur Flexser wrote:
> Actually, I don't know for sure if the KEY264K used peeks and pokes to
> share data between the two banks, and switched via interrupts.  I only know
> the program from having skimmed some of its docs a long time ago.  But now
> that I think about it, it seems to me that things could also be set up to
> allow the two banks to both have access to the same Basic variables and
> arrays, by manipulating pointers to the variable space so that they matched
> up between the two banks.
>
> Art
>
> On Mon, Jan 21, 2019 at 10:17 PM Arthur Flexser <flexser at fiu.edu> wrote:
>
>> This switching of 32K banks is exactly what the KEY264K program does.
>> They had it so you could either run 2 programs independently, each in one
>> bank, or have the bank switching controlled by interrupts so that in
>> effect, the two programs time-shared with one another and perhaps could
>> access common data via peeks and pokes.
>>
>> Art
>>
>> On Mon, Jan 21, 2019 at 9:44 PM Robert Gault <robert.gault at att.net> wrote:
>>
>>> Don't know the name of those programs but take a look at the specs for
>>> the SN74LS783 (SAM) chip.
>>> You will see that in addition to all RAM and RAM/ROM ($FFDF/$FFDE) you
>>> can page switch. With 64k RAM
>>> installed, writing to $FFD4 gives (page0) normal 32k RAM, but writing to
>>> $FFD5 (page1) and your
>>> unused 32k is active. Since page switching leaves the ROM present, you
>>> might be able to have Basic
>>> programs switch pages and in effect use 64k of RAM.
>>>
>>> Robert
>>>
>>> L. Curtis Boyle wrote:
>>>> There were some commercial programs that allowed two 32k BASIC programs
>>> (after a little ML setup, it kept your ROM’s in the upper 32k, and bank
>>> switched two 32k RAM banks in the lower half. Can’t remember the names of
>>> them, though, off the top of my head.
>>>>
>>>> Sent from my iPhone
>>>
>>>
>