[Coco] Preliminary Support for SDC in HDBDOS

[William Astle]

On 14-11-25 03:59 PM, Arthur Flexser wrote:
> On Tue, Nov 25, 2014 at 5:19 PM, William Astle <lost at l-w.ca> wrote:
>
>>
>> 2. Interrupts. You need to make sure that any interrupt handling does not
>> occur in the upper 8K of the "ROM" space since that will crash when the map
>> is switched. Disabling interrupts would be overkill, though, since you can
>> just make certain that no interrupt handling happens in the upper 8K.
>>
>
> Disabling interrupts when dropping into ROM mode would definitely not be
> overkill if you want this modified ROM to be able to run software that
> might be putting its interrupt handling anywhere at all.

Yes, that's a fair point. One would also want to make sure any DSKCON 
extensions located in the upper 8K could handle the data buffer being in 
"high" RAM, too, for the same reason.

That said, how much such software is out there? That is, software that 
uses RAM above disk basic while still actually using the disk ROM? Of 
that software, how much of it actually modifies the interrupt handling 
with a routine in high RAM?