[Coco] Having fun with hacking HDB-DOS

[Arthur Flexser]

In Extended ADOS-3, I used the technique of temporarily going to ROM mode
whenever the upper half of the 16K ROM needed to be accessed.  That way
Super Extended Basic in RAM (as usual) could coexist with the code in the
upper 8K of the EPROM, so all CoCo 3 commands would automatically work.
Plus, software compatibility was excellent because nothing could have
memory conflicts with code in the EPROM's upper 8K, since that code was
switched out of the memory map except when being accessed.  This also meant
more room for extensions, since no EPROM space was wasted in duplicating
what was already there in Super Extended Basic.

Perhaps you could use that technique for your extended HDB-DOS?

Art


On Thu, Feb 13, 2014 at 10:53 PM, Juan Castro <jccyc1965 at gmail.com> wrote:

> Now the WIDTH command works and drops you in the PMODE 4 screen if the
> argument is 51 or 64. WIDTH 32 takes you back to text mode. Also, all
> CoCo 3 tokens are recognized. But, of course, all but WIDTH will give
> you an error.
>
> Next up: LOCATE. Then... BUTTON? ERR/ERNO/ERLIN?
>
> ROMs: https://dl.dropboxusercontent.com/u/15643089/16kroms.zip
> Source patch:
> https://dl.dropboxusercontent.com/u/15643089/hdbdos-16krom.patch
>
> Juan
>
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