[Coco] Four slot MPI project

[Gene Heskett]

On Tuesday 24 July 2018 15:36:01 Zippster wrote:

> Hi Gene,
>
> > On Jul 24, 2018, at 12:55 PM, Gene Heskett <gheskett at shentel.net>
> > wrote:
> >
> > Looks great Ed. Only comment is your beard, its way too black. :-)
>
> I’m working on it.  :)
>
> > Projected price yet?
>
> I’m not 100%, but it’s looking like $140 with the case and power
> adapter.
>
> - Ed
>
That, in todays market, doesn't sound too bad, I could be interested in 
one when its ready.

Now, let me throw something else your way. Hard drives tend to be fickle, 
and while I have removed them in order to give the corner of the shell a 
tap with a soft hammer just to break the stiction and get them started, 
and they'll run as long as they aren't turned off for another extended 
period of time like mine have been for around 2 years because I had 
around $12k worth of water control work, involving jackhammers and such 
damaging dirt makers at work for several days, and TBT I haven't yet 
totally restored things.

So, what we as a group, I hear figures from the man that we are over 500 
strong just on this list.

Solid state drives are seemingly in freefall WRT prices, I just bought 3 
60GB's for my cnc machinery for less than 75 cents a gigabyte. A 60GB is 
sublime overkill for a coco as its out of math ability at 4GB.

But we seriously need a sata interface, and to widen the market count, it 
should not be an adapter from scsi to sata, as that would limit it to 
use with the relatively few scsi interfaces about. It should plug 
directly into a multi-pack. And because the drives are huge in 
comparison to what the coco can address, how about a dip switch to set 
the offset such that it could mimic 50 or so 2GB drives. Or even a 
register that could be poked from the startup to set that offset 
for /s1, leaving /s0 available as the default boot drive, but all on one 
SSD.

There would of course be a huge data speed differential, but reading and 
writing a single 512 byte block at a time should make that a never mind 
as long as the buffer in the controller can handle 500megs/second either 
direction. The ones I have put in service are making 300 to 700 megs a 
second. Since the coco's max transfer is 11 second per megabyte, the 
apparent speed will not be seen, other than the lack of seeking time 
since the SSD's don't have any. This is what one of them, attached to a 
rock64 viaits usb-3 port, reports:

gene at rock64:~$ sudo hdparm -Tt /dev/sda3
[sudo] password for gene:

/dev/sda3:
 Timing cached reads:   1592 MB in  2.00 seconds = 796.28 MB/sec
 Timing buffered disk reads: 772 MB in  3.01 seconds = 256.80 MB/sec

That, the coco's will never see. But since drive tech is moving hell bent 
to SSD's we could sure use a modern storage format.

Here is another of them, but its on a usb-2 port, which kills its speed 
but is still magnitudes faster than the coco's:

pi at picnc:~ $ sudo hdparm -Tt /dev/sda3

/dev/sda3:
 Timing cached reads:   952 MB in  2.00 seconds = 475.46 MB/sec
 Timing buffered disk reads:  72 MB in  3.04 seconds =  23.66 MB/sec

What say you about that?  We really do need a sata drive interface, 
preferably with 2 ports so we can do backups.

-- 
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>