11 Aug
2006
11 Aug
'06
9:14 p.m.
Hi,
I ran across an interesting gadget at a university surplus sale, maybe someone
can tell me how useful it is. It's an EX 2000 Disk Drive Tester. It came
with a couple manuals and some 5.25" alignment floppies. The manual says it's
"used to align and repair floppy disk drives with industry standard SA400 and
SA800 interfaces", and says the connections on the end are for 5.25" and
8"
drives. Here's a photo:
http://www.soupwizard.com/temp/ex2000.jpg
I'm extremely unlikely to be doing any floppy repairs myself, so would this be
useful to anyone else?
Jeff
12 Aug
12 Aug
10:55 a.m.
On Saturday 12 August 2006 12:14 am, Jeff Davis wrote:
Hi,
I ran across an interesting gadget at a university surplus sale, maybe
someone can tell me how useful it is. It's an EX 2000 Disk Drive Tester.
It came with a couple manuals and some 5.25" alignment floppies. The
manual says it's "used to align and repair floppy disk drives with industry
standard SA400 and SA800 interfaces", and says the connections on the end
are for 5.25" and 8" drives. Here's a photo:
http://www.soupwizard.com/temp/ex2000.jpg
I'm extremely unlikely to be doing any floppy repairs myself, so would this
be useful to anyone else?
I used to do drive alignments way back when, and probably still have an
alignment disk or two stashed away somewhere (though I never did get my hands
on an 8" one :-). With 5.25" drives going away pretty much in the PC
context, the bottom having dropped out of the commodore market some years
back, and the price of 3.5" drives being what they are, I don't know how
worth while it'd be to even bother with it.
Not that I'd toss it if one of those were to come my way...
Somewhere I also have a "drive exerciser" cartridge that plugged into a Yamaha
CX-5 computer as well -- this was no doubt meant for their drive but would
work equally well with any other drive that could be plugged in and powered
up if you adjusted the value of the maximum track number, which was easy
enough to do in the software since it ran in BASIC. It came in handy a few
times.
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, a critter that can
be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin
3:07 p.m.
Not that I'd toss it if one of those were to come
my way...
Somewhere I also have a "drive exerciser" cartridge that plugged into a Yamaha
CX-5 computer as well -- this was no doubt meant for their drive but would
work equally well with any other drive that could be plugged in and powered
up if you adjusted the value of the maximum track number, which was easy
enough to do in the software since it ran in BASIC. It came in handy a few
times.
What exactly does the "drive excerciser" do which comes in handy? -- I've
got
some diagnostics and drive test tools built into ImageDisk which I find very useful,
and I'd be happy to add any other such functions that folks need (provided of
course that it can be done with the PC hardware).
Dave
--
dave06a (at) Dave Dunfield
dunfield (dot) Firmware development services & tools: www.dunfield.com
com Collector of vintage computing equipment:
http://www.classiccmp.org/dunfield/index.html
2:36 p.m.
On 8/12/2006 at 5:07 PM Dave Dunfield wrote:
What exactly does the "drive excerciser" do
which comes in handy? -- I've
got some diagnostics and drive test tools built into ImageDisk which I
find
very useful, and I'd be happy to add any other such
functions that folks
need (provided of course that it can be done with the PC hardware).
Doing a good job on drive alignment generally requires an alignment
diskette and a 'scope. However, there were alignment diskettes produced
with tracks that were skewed across the width of a track. The idea being
that you listed the sectors that could be read and that would tell you
approximately how far off alignment you were.
Back in the belt-drive DC motor days, things like Instantaneous Speed
Variation were important, but you don't see that being tested on the
direct-drive models now. Just a simple averaged speed check is adequate on
modern drives.
Leadscrew positioners (or even the cam-and-follower type in the SA400)
sometimes display backlash, which can be checked with an alignment diskette
by approaching the same track from the inside and the outside tracks.
Taut-band positioners generally don't show much backlash. But in the bad
old days, recovery from a data error could took the form of:
1. Re-read in place 3 trimes
2. Recalibrate (seek to track zero), seek to track and re-read
3. Recalibrate, seek past the track and then step backwards and re-read
4. Recalibrate, single-step to the track and re-read.
What the first accomplishes is pretty obvious. The second attempts to make
sure that the head position hasn't drifted and also tries to knock any
schmutz loose from the head. The third attempts to compensate for backlash
in the positioner. The fourth tries to anticipate a slugglish positioner
mechanism.
Cheers,
Chuck
13 Aug
13 Aug
3:47 a.m.
What exactly
does the "drive excerciser" do which comes in handy? -- I've
got some diagnostics and drive test tools built into ImageDisk which I find
very useful, and I'd be happy to add any other such functions that folks
need (provided of course that it can be done with the PC hardware).
Doing a good job on drive alignment generally requires an alignment
diskette and a 'scope. However, there were alignment diskettes produced
with tracks that were skewed across the width of a track. The idea being
that you listed the sectors that could be read and that would tell you
approximately how far off alignment you were. Back in the belt-drive DC motor days, things like
Instantaneous Speed
Variation were important, but you don't see that being tested on the
direct-drive models now. Just a simple averaged speed check is adequate on
modern drives.
Tricky to do with PC hardware - I suppose you could time the interval between
each ID in a read-ID loop, however the ISV of the drive that formatted the disk
would also have an effect on your results. Again a "known good disk" would
be required.
Is this a function that would be worth putting into ImageDisks test menu?
I personally don't think so... I don't think I've ever seen a drive where the
ISV
was bad enough to prevent reading... But it might be handy just to keep an
eye on how your older drives are performing.
Leadscrew positioners (or even the cam-and-follower
type in the SA400)
sometimes display backlash, which can be checked with an alignment diskette
by approaching the same track from the inside and the outside tracks.
Taut-band positioners generally don't show much backlash. But in the bad
old days, recovery from a data error could took the form of:
1. Re-read in place 3 trimes
2. Recalibrate (seek to track zero), seek to track and re-read
3. Recalibrate, seek past the track and then step backwards and re-read
A variation of #3 is step out and back (faster than recalibrate) - ImageDisk
does all of these.
I'll add another rather unorthodox one - power the drive motor off and back
on. Not useful in standard usage, however when reading forign formats on
a PC, believe it or not, I've seen disks where the first or last sector on the
track can't be read at full speed, but can be read as the drive is coming
up to speed. When set to it's maxium "try and get it no matter what",
ImageDisk will do this, and it has enabled me to read a couple of disks
that I "just couldn't get" by other means.
4. Recalibrate, single-step to the track and re-read.
This one I don't do - It's main use is to compensate for drives that are
too slow for the step rate - since ImageDisk typically only done one track
at a time steps, I simply use a nice low step rate (and let the user
reprogram it if he wants).
Dave
--
dave06a (at) Dave Dunfield
dunfield (dot) Firmware development services & tools: www.dunfield.com
com Collector of vintage computing equipment:
http://www.classiccmp.org/dunfield/index.html
12 Aug
12 Aug
5:28 p.m.
On Saturday 12 August 2006 06:07 pm, Dave Dunfield wrote:
It's been ages since I used it, probably last in about the 1990-2 timeframe,
but the main thing is to be able to read out the drive's speed in RPM (I
guess they use the index pulse for that?) and to be able to step the drive to
specific tracks, which is where the alignment disk comes in to the picture.
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, a critter that can
be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin
Not that
I'd toss it if one of those were to come my way...
Somewhere I also have a "drive exerciser" cartridge that plugged into a
Yamaha CX-5 computer as well -- this was no doubt meant for their drive
but would work equally well with any other drive that could be plugged in
and powered up if you adjusted the value of the maximum track number,
which was easy enough to do in the software since it ran in BASIC. It
came in handy a few times.
What exactly does the "drive excerciser" do which comes in handy? -- I've
got some diagnostics and drive test tools built into ImageDisk which I find
very useful, and I'd be happy to add any other such functions that folks
need (provided of course that it can be done with the PC hardware).
13 Aug
13 Aug
3:47 a.m.
What exactly
does the "drive excerciser" do which comes in handy? -- I've
got some diagnostics and drive test tools built into ImageDisk which I find
very useful, and I'd be happy to add any other such functions that folks
need (provided of course that it can be done with the PC hardware).
It's been ages since I used it, probably last in about the 1990-2 timeframe,
but the main thing is to be able to read out the drive's speed in RPM (I
guess they use the index pulse for that?) and to be able to step the drive to
specific tracks, which is where the alignment disk comes in to the picture. 
3:19 p.m.
What
exactly does the "drive excerciser" do which comes in handy? -- I've
got some diagnostics and drive test tools built into ImageDisk which I find
very useful, and I'd be happy to add any other such functions that folks
need (provided of course that it can be done with the PC hardware).
It's been ages since I used it, probably last in about the 1990-2 timeframe,
but the main thing is to be able to read out the drive's speed in RPM (I
guess they use the index pulse for that?) and to be able to step the drive to
specific tracks, which is where the alignment disk comes in to the picture.
You can also step the drive to any track, analyze tracks, read tracks, format
tracks, write tracks and see the results of a continuous read-id loop all under
full manual control, and with a real-time display of the Fault, Ready, Double-
sided, Write-protect and Track-0 indications from the drive as well as the
sector-IDs passing under the head.
You are assuming the disk is readable by a PC controller. Which may well
not be the case.
I was just curious if there were any other functions
built into the specialized
drive tester that I have not yet covered... Never owned/used such a piece of
equipment myself...
One other advantage of the drive exerciser I use is that it's about the
size of a multimter. Trying to set up a PC system and cable it to a drive
I am repairing would be almost impossible. But the exerciser will fit
onto my workbench surrounded by bits of classic computer.
-tony
4:10 p.m.
On 8/13/2006 at 11:19 PM ard at p850ug1.demon.co.uk wrote:
The spindle speed is close enough for the data
separator PLL to lock to
the signal from the read chain
Funny thing about that--which goes to show you some wisdom about old
software vs. new. While Windoze can barely figure out what kind of disk
you have in the drive (and sometimes even if there's one in the drive), I
powered up an old CP/M system here to read some old GCR disks.
One of the first things that I did was to format a diskette. So, I typed
in the command and gave it the usual "G" to go and format and was greeted
with
the message:
FORMAT ABORTED--SPINDLE SPEED IS 7% SLOW.
The cure was to get the drive testing program out and tweak the pot on the
tach board, but it was a lesson in how, sometimes, the old software on
those poor crippled machines is far from brain-dead.
Cheers,
Chuck
6:26 p.m.
On Sunday 13 August 2006 07:10 pm, Chuck Guzis wrote:
On 8/13/2006 at 11:19 PM ard at p850ug1.demon.co.uk
wrote:
That's pretty impressive, what sort of a cp/m box was that?
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, a critter that can
be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin
The spindle speed is close enough for the data
separator PLL to lock to
the signal from the read chain
Funny thing about that--which goes to show you some wisdom about old
software vs. new. While Windoze can barely figure out what kind of disk
you have in the drive (and sometimes even if there's one in the drive), I
powered up an old CP/M system here to read some old GCR disks.
One of the first things that I did was to format a diskette. So, I typed
in the command and gave it the usual "G" to go and format and was greeted
with the message:
FORMAT ABORTED--SPINDLE SPEED IS 7% SLOW.
The cure was to get the drive testing program out and tweak the pot on the
tach board, but it was a lesson in how, sometimes, the old software on
those poor crippled machines is far from brain-dead. 
8:34 p.m.
>That's pretty impressive, what sort of a cp/m
box was that?
On Sun, 13 Aug 2006, Chuck Guzis wrote:
Durango F85 CP/M 2.2. (Guess who wrote the format
utility? :) I'd
forgotten about the speed test.)
So, as compared to the multi-megabyte fUtility in Windoze, you
could say that the programmers of yore have forgotten more than
MS knows.
8:43 p.m.
On 8/13/2006 at 8:34 PM Fred Cisin wrote:
So, as compared to the multi-megabyte fUtility in
Windoze, you
could say that the programmers of yore have forgotten more than
MS knows.
Maybe, but sometimes it's like working in a dead language. I think
systems-level (not applications) programmers of yesteryear were more aware
of the underlying hardware and its foibles.
Cheers,
Chuck
14 Aug
14 Aug
10:50 a.m.
On Sunday 13 August 2006 11:20 pm, Chuck Guzis wrote:
On 8/13/2006 at 9:26 PM Roy J. Tellason wrote:
Never heard of that one, or if I did I don't remember...
That's pretty impressive, what sort of a cp/m
box was that?
Durango F85 CP/M 2.2. (Guess who wrote the format utility? :) I'd
forgotten about the speed
test.)
I've no idea.
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, a critter that can
be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin
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