[Coco] DriveWire on EPROM ?

[Arthur Flexser]

The original version of that internal ROM is coded so as to include booting
up the Color Basic and Extended Basic images that the chip contains, plus
booting up Disk Basic if it is present in the disk controller.

To do more would require additional coding.  You couldn't just "pop in"
some code that was written to be booted via inclusion in the Disk Basic
chip.

Art

On Mon, Jan 18, 2016 at 3:50 PM, Jason M <oleribus at gmail.com> wrote:

> perhaps I'm not using the right terms ... my chip is removable ... the chip
> that was in there had a custom image that my company had developed back in
> the day ...
>
> a co-worker used his old EPROM writer to put color basic 2 image on a
> M27C256B chip, I popped it in the coco and it booted right up ... that was
> a 32K rom.
>
> On Mon, Jan 18, 2016 at 3:38 PM, Arthur Flexser <flexser at fiu.edu> wrote:
>
> > A significant problem with replacing the internal ROM chip with an EPROM
> is
> > that the chip is soldered in. For that reason, no one to my knowledge has
> > bothered to explore putting enhancements in that chip rather than in the
> > disk controller one.  The internal chip does have enough free space for
> > substantial additional code.  The Mugateers image that appears when you
> > press control-alt-reset takes 6K in itself and could be replaced by code.
> >
> > However, you'd have to write some specialized routines to make use of
> such
> > code, whereas putting it in the disk controller uses the bootup sequence
> > already built into Basic.
> >
> > Art
> >
> > On Mon, Jan 18, 2016 at 3:13 PM, Jason M <oleribus at gmail.com> wrote:
> >
> > > Is there a way to load HDB-DOS or DW3DOS from the EPROM on the main
> > board ?
> > > Which I believe is a 32K chip. The rom images I'm finding look like
> they
> > > are 8K and are for a Disk Controler EPROM ?
> > >
> > > Thanks,
> > > JasonM
> > >
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