[Coco] IDE interfaces
gheskett at wdtv.com
Tue Mar 15 09:04:17 EDT 2016
On Tuesday 15 March 2016 04:16:51 Tormod Volden wrote:
> On Tue, Mar 15, 2016 at 7:09 AM, Doug Fraser wrote:
> > I'm looking for an IDE interface to replace my Burke n Burke
> > adapter. Does anyone know where I can acquire one?
> At least a while ago there were still Glenside IDE boards to be had.
> They are supported by HDB-DOS and NitrOS-9.
> If there are no boards left we should try to have more made. Maybe
> somebody is working on it, because request about schematics come up
> from time to time.
Lets look at reality Tormod. And that is that if new boards are made,
they should be designed to handle sata drives simply because that is all
we can buy today. Anything we can pick up at a flea market today, quite
likely has had its 50,000 hours of spin time and isat best using a cane
to get around like I am.
I think possibly a few dollars more expensive because that likely would
have to have not only the interface chip, but there would need to be a
fpga translation and buffer memory just to bridge the gap between bus
speeds. Current sata drives can move data at 6GB/second, so seek time
is the random access speed limiter but at the coco's speed that is a
Physical sector sizes are presently at 4096 bytes a sector in new
rotating media, and I've heard rumors that there are drives with 32768
sector sizes on the horizon, so a new interface would have to translate
that into a 256 byte sector slices for the coco. We already do the
512/256 translation in the drivers, but IMO that really belongs in the
controller, which with modern hardware could handle that in 64 to 256
byte wide pieces per machine cycle of its hardware.
Or am I dreaming? The only seemingly future-proof interface, scsi, has
been rendered obsolete by lack of new drives in the pipelines. And now
ide/atapi stuff is a minimum of 15 years old. And with its
unterminated interfaces restricting cable lengths to nominally 15 to 18
inches, which finally did get some impedance matching about the time the
80 wire cable showed up, but done so poorly that its like a pig, no
matter how much lipstick you put on it, its STILL a pig.
I was initially spooky about sata, but so far, the only problems I have
had with it have been that "hot red" cabling supplied by about 99% of
That particular dye in a cables insulation has been known as a time bomb
by me from back in the early 70's when it became populer in CB radio
microphone cable, it slowly turns the copper conductor its wrapped
around into a copper oxide powder, a very poor conductor. Takes from 3
to 5 years to fail. Replace them with any other color of cable and
you'll have no further problems with your sata stuffs.
This machine, with 6 sata ports in its motherboard, has had the red ones
I built it with nearly a decade ago all replaced with some other color,
and I can go poking around it its internals now without blasting the
system log with 100k of sata reset messages because the red cable is
crap after a few years.
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>
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