[Coco] [ColorComputer] Diagnostic ROM

[RETRO Innovations]

On 12/16/2025 9:51 AM, Alex Evans via groups.io wrote:
> There is a major shortcoming I should address. The data in ROMS that 
> are overlaid by the diagnostic pak. For the CoCo3, this is relatively 
> easy to accomplish. I can copy some code into RAM and switch the ROM 
> mode to 32k internal. Run the code and switch back. For the CoCo 1/2 
> and Dragon 32, this isn't an issue as the program pak doesn't overlay 
> any of the ROMS. However for the Dragon 64, this is actually an issue. 
> As I understand it the Dragon 64 has two BASIC ROMs, one in the Usual 
> location that is for running in 32k RAM mode and another that is 
> copied to upper RAM to allow for more space in BASIC in all RAM mode. 
> This ROM is (IIRC) mapped from $C000 to $FFEF and is normally disabled 
> when there is a program pak inserted.
>
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Can the copy code to ram option be used to address the D64 issue, or is 
the Program Pak insertion hardwired to disable this ROM?

Jim

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