24 Apr
2007
24 Apr
'07
7:54 a.m.
Subject: Re: Junkbox CP/M system?
From: "Ensor" <classiccmp at memory-alpha.org.uk>
Date: Tue, 24 Apr 2007 05:16:45 +0100
To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at
classiccmp.org>
Hi,
It's rarely implemented and its not a "line" it was part of the command
set.
The line IO16 is an output that goes high when sector transfers happen.
I have a few XT IDE and of the 4 only one drive (20mb) does 8bit the rest
depend on the ISA bus card to do translation (8-16).
CF IDE is easy--it's 8 bit. HD IDE uses a
16-bit data path for
sector data transfer....
The original IDE drives used 8-bit transfers (I had one in my first XT),
even to this day there is still be a signal on the IDE interface to force
the use of 8-bit mode.
At least one of the IDE interfaces available for 8-bit Atari machines uses
the drive in this mode.
TTFN - Pete.
What drive? YOu can of course use CF that has 8bit mode or just ignore
the high 8bits (loose half the space) for a simpler interface.
Allison
25 Apr
25 Apr
9:35 p.m.
Hi,
I didn't look into it deeply enough to find out what drive they recommend, I
was just browsing through some postings in one of the Atari newsgroups and
saw mention of it.
It's rarely implemented and its not a
"line" it was part of
the command set....
It's been probably 12 years since I looked at the IDE spec (or the pinout of
an IDE port for that matter) but I was sure I remembered seeing a signal on
the connector which, when asserted, forced the drive to work in "8-bit"
mode? No?
Wonder what I'm confusing it with then...?
I have a few XT IDE and of the 4 only one drive (20mb)
does 8bit
the rest depend on the ISA bus card to do translation (8-16).
WD did a (shortlived ISTR) line of 8-bit IDE drives, I had one - along with
the associated ISA bus card. I forget the model number, but they were
differentiated from the otherwise identical "16-bit" versions by having an
"XT" suffix on the model number.
And they were bl**dy unreliable too! :-(
These came out shortly after WD acquired(?) Tandon; they were basically 3.5"
Tandon RLL drives with a WD IDE controller in place of the Tandon
electronics, IYSWIM?
From what you and Chuck have said, do I assume that
either a) this "8-bit"
mode was never very widespread and/or b) this mode
was dropped from the
specification somewhere along the line (E-IDE perhaps)?
I must admit I've not kept up with developments in IDE, I switched to SCSI
in 1991 and never bought another IDE drive until last year....
At least one
of the IDE interfaces available for 8-bit Atari machines
uses the drive in this mode.
What drive? YOu can of course use CF that has 8bit mode or just ignore
the high 8bits (loose half the space) for a simpler interface. From the little I read, I understand that most of the
available interfaces
do exactly what you suggest and "waste" half of the
available space. I got
the impression that one of these interfaces could run the drive in 8-bit
mode, though from what you say it probably has to be a very specific (old)
drive....or maybe the guy was referring to using a CF card, quite a few
people seem to be using them in this manner?
I'll go do some more digging, I'm intrigued now.... :-)
TTFN - Pete.
26 Apr
26 Apr
7:28 a.m.
Ensor wrote:
Hmm, I think that's what's in my Amiga A590 enclosure. It's certainly not
SCSI, but I'm sure the connector's not proper IDE either.
I have a few
XT IDE and of the 4 only one drive (20mb) does 8bit
the rest depend on the ISA bus card to do translation (8-16).
WD did a (shortlived ISTR) line of 8-bit IDE drives, I had one - along
with the associated ISA bus card. I forget the model number, but they
were differentiated from the otherwise identical "16-bit" versions by
having an "XT" suffix on the model number. And they were bl**dy unreliable too! :-(
That worries me about the Amiga one. It does have a SCSI connector within the
A590 I think, but I'm not sure how picky it is about what drives it'll work with.
I must admit I've not kept up with developments in
IDE, I switched to
SCSI in 1991 and never bought another IDE drive until last year....
I did that too... I've sort of given up on SCSI now for drives though, simply
because the prices for tested/used IDE drives [1] are so much cheaper than
SCSI, and for storage of things like scans and images I don't *need* the
performance. It'd be different if it were for systems that were on the 'net or
accessed by several people, of course, but for "home personal fileserver" IDE
seems to be working out (even if it does make me feel all unclean ;)
[1] I don't buy new stuff, not for PCs - not when the price drops so much for
"previous generation". Unfortunately SCSI drives of 36GB and up don't seem
to
be readily available.
cheers
Jules
28 Apr
28 Apr
1:01 a.m.
Hi,
I'd tentatively say that if you have a working one, it'll likely keep
working for a while to come.
All the ones that I and several friends bought either failed within the
first couple of months, or failed about 2 months after the guarantee
expired...! If you have one that still works I'd say you've got one of the
good ones. ;-)
BTW The failure in our cases was that the drive failed to spin up
properly/couldn't get up to speed.
And they were
bl**dy unreliable too! :-(
That worries me about the Amiga one.... I did that too... I've sort of given up on SCSI
now for drives
though, simply because the prices for tested/used IDE drives [1]
are so much cheaper than SCSI, and for storage of things like scans
and images I don't *need* the performance.
The reason I've been using SCSI up till now wasn't for the performance of
the drives as such. More because of the fact that the SCSI subsystem is an
intelligent susbystem an puts far fewer demands on Windows than IDE does.
It makes for a far "smoother" running system, I'm constantly irritated by
the little pauses and stutters whenever Windows accesses an IDE drive (this
is true even in the case of these two "high performance" IDE drives I'm
using now).
If it wasn't for the racket my SCSI drives make (I always run at least three
in my configuration, sounds like it's about to take off!!) I'd switch back
to them in a flash.
I'm thinking about investigating SATA as the drives are very cheap now, but
from the little information I've seen thus far,
it's essentially just the
cabling that's changed and the system has to
service them in the same manner
as parallel IDE?
[1] I don't buy new stuff, not for PCs - not when
the price drops so
much for "previous generation"....
Same here, there's far too much of a premium on the latest gear. My attitude
to PC's now is pretty much "So what if it's last year's model, you paid 8
times more for it than I just did....and it still works just as well". :-)
I got really tired of buying the latest bit of gear, only to see the price
halve in the space of a couple of months.
....Unfortunately SCSI drives of 36GB and up don't
seem to be
readily available.
Haven't looked on eBay for a while, but there used to be loads on there
around 18 months ago. They tended to come and go in waves on there, one week
there'd be loads, the next nothing....you can get some real bargains too if
you put in a bit of time searching (last time I got a pair of brand new,
unused, 70 odd GB Seagates for ?25 each, SCA-80 connectors and surprisingly
unpopular despite the adapters only being about ?3).
TTFN - Pete.
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3 comments
3 participants
participants (3)
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ajp166＠bellatlantic.net -
classiccmp＠memory-alpha.org.uk -
julesrichardsonuk＠yahoo.co.uk