[Coco] working with the sdc

[Gene Heskett]

On Monday 05 November 2018 12:04:54 rietveld rietveld wrote:

> I use the SDC to launch DW which in turn starts Os9 lv2 via sidekick. 
>  I assume that you can do the same to boot nitros9

Sidekick? Thats new to me I'm afraid.  Tell me more plz.

More below...

> I'd intend that it would boot nitros9 at powerup if thats possible,
> but I see a problem. Since LSN0 needs to be updated each time you
> select a different os9boot file that (AIUI) 4k block will need to be
> erased, and a master copy from someplace else on the sdc, needs to be
> written back to track 0 with those 5 bytes being edited on the fly. My
> bootlink, nor the basic version on vdisk-0 of my present setup doesn't
> do that since it assumes a hard disk with unlimited read/modify/write
> cycles ability. Once up and running, I can fix my "bootlink" to do
> that, but that brings up the question of how many such erase/re-write
> cycles can we expect a modern sd card to survive?
>
> Interesting question.  And one that points to a wish for the sdc,
> modified to use a sata drive since prices there are in freefall. I can
> by SSD's of 40 to 60 Gb for around $30, which is plenty big enough to
> run LinuxCNC from, so I'm replaceing all the spinning rust drives as
> they fail with those SSD's, gaining speed that makes the machine load
> and run whatever with a dual core cpu running at 1400 Mhz, act like
> its a eight core running at 10 GHz.
>
> So Ed, since I know you are copying the mail, whats chances of a new
> sdc pack, with the sdc socket space swapped for a sata socket or 2?
>
> These modern SSD's do all that management and wear leveling
> internally, and my busiest machine isn't aware of a spare block
> re-assignment so far in around 2 years. Although I do see a fudged
> value from the
> power-on-hour column for both of the drives running right now, one
> says 89xx hours, just into the 2nd year, and I know its longer than
> that, and the other is reporting a number thats about the age of the
> known universe, and neither is reporting a swapped block.
> So just for grins I've initiated a -t long self test that will smell
> every corner it has on both of them.


I'd trim, but there are unanswered questions yet. Like how big an sd card 
can I actually use?

I just made another pass at getting the seagate 1Gb scsi drives started, 
and got both of them running again by aiming a small plastic hammer at 
the front mounting screws on the right side of the drive cage.  So 
nitros9 booted right up from drive /dd (0) and a dir of /s1 also showed 
the other one was up and running.

Now, this is by way of hdb-dos, but it knows nothing about the sdc so its 
invisible. That boot started by reading track 34 from hdb-dos's vdisk 
128.

So what I propose to do is to fire up dw on this box, "touch" a file 
called ns9drv0.dsk, mount it with the dw gui, and backup drive /dd@ to 
the dw descriptor (I think its /x0) in this boot. This should give me a 
bootable image accessible by the drivewire cable. I think.  Whats wrong 
with this assumption?

-- 
Cheers, Gene Heskett
--
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page <http://geneslinuxbox.net:6309/gene>