[Coco] NitrOS-9 instant boot CoCo

[Joel Ewy]

Robert Gault wrote:
> Roger Taylor wrote:
>> I'm trying to gather the setups some of you OS-9/NitrOS-9 users have
>> in place that allows you to hit the power button on your CoCo then
>> have the OS-9 prompt within a few seconds, with no moving hard drives
>> or MPI, or DriveWire cable (although that's a very nice idea).
>>
>> Can the SuperIDE interface do this, and if so, what add-ons are
>> needed?  What about a NItrOS-9 ROM that completely boots up from the
>> ROM?  If so, can this ROM be put on a 32 kByte EPROM and replace the
>> CoCo 3 ROM.  What about piggybacking an EPROM on the CoCo motherboard
>> and clipping some pins on the old ROM?  Anyone done this kind of hack
>> to avoid the infamous killer desolder job?
>>
>
>  The "problem" with booting from a ROM as Roger asks rather than a
> hard drive, is that you are locked into at least a specific kernel.
> That means cobbler and os9gen have lost some of their usefulness. It
> is important to be able to make changes to the core OS-9/NitrOS-9
> modules at will as needed without needing to burn a new EPROM.
I wouldn't call it a "problem" so much as a "trade-off".  It would be no
different from running (D)ECB from ROM, except that you would have an
arguably better OS in your ROM.  But the latency between power-on and
cursor would be negligible booting from ROM, and only minimal booting
from IDE/CF.  Though IDE/CF would certainly be the next best thing to
ROM, especially if you have an auto-boot ROM installed.

The ideal, of course, would be to boot NitrOS-9 directly from a Flash
ROM that could be updated with a new kernel.  Best of both worlds.
>  Using a CF card more easily reloaded with new code should be just as
> good as booting from hard drive directly.
>
Even better of course, because you have no physical r/w heads to move
around or crash, no spindle motor bearing to wear out, no platters to
scratch, lower power consumption (by far!), less heat, and a much
smaller package.
>  At the moment the size of a typical NitrOS-9 OS9Boot file plus kernel
> is about 12.5K. It would certainly fit into a ROM. However, if you
> plan to include the CMDS directory as well, forget it!
>  It is not enough to load just the OS9Boot file to run OS-9. You also
> need all of the commands and software. Where would they be without
> some type of drive system unless you use a very large CF card?
>
But of course, (D)ECB doesn't include all the programs you might want in
ROM either.  Having attached mass-storage and booting off of it are two
different things.  I like the idea of having the kernel, drivers for
essential built-in hardware, a shell, and a few must-have commands in
(Flash)ROM, and available at the touch of the power switch.  The rest
(including drivers and descriptors (and maybe even file managers?) for
other peripherals (printers, auxiliary drives, serial/network, e.g.) can
be loaded from mass-storage when / if needed.

I remember reading that OS-9 was designed with the idea in mind that
device driver modules could be distributed in ROM chips along with
expansion boards.  I never saw that idea implemented, but I thought it
was a great notion.  Plug in your FDC and the driver for it is detected
and loaded automatically.  Flash ROMs weren't around at the time that
idea was current, but updated in that way, I think it would be a really
spiffy thing for the CoCo.

JCE

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