1 Mar
2011
1 Mar
'11
4:20 a.m.
Hi guys,
I'm trying to track down an 8-inch floppy drive to read an Intel MDS
M2FM disc I've been sent for adding to the DiscFerret decoder engine.
Specifically: it's an ISIS boot floppy, in SS/DD format.
Does anyone have a spare 8in drive gathering dust in a corner somewhere?
Based on the prices on Greed-Bay, I get the impression most of the
sellers have been engaging in some form of abuse of illicit
substances.... I mean, seriously, $700 for a Shugart 801, "untested"
(which would seem to be a synonym for "I know it's broken but I sure as
hell won't admit it!") and missing the head-amp / motor control PCB?
Thanks,
--
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/
1 Mar
1 Mar
11:58 a.m.
Hi guys,
I'm trying to track down an 8-inch floppy drive to read an Intel MDS
M2FM disc I've been sent for adding to the DiscFerret decoder engine.
Specifically: it's an ISIS boot floppy, in SS/DD format.
Does anyone have a spare 8in drive gathering dust in a corner somewhere?
Based on the prices on Greed-Bay, I get the impression most of the
sellers have been engaging in some form of abuse of illicit
substances.... I mean, seriously, $700 for a Shugart 801, "untested"
(which would seem to be a synonym for "I know it's broken but I sure as
hell won't admit it!") and missing the head-amp / motor control PCB?
AFAIK, SA801s have one PCB which includes the read/write chain and
stepepr controlelr, etc. There is no spindle motor controller, of course.
I'd better expand on that last part becuase it may affect you buying a
drive second-hand. Msot, (but not all) 8" drives have cpacitor-run AC
spindle motors. Their speed is therefor set by the mains frequency.
I ahve seen both 15V and 230V motors in SA800s. Both will run off either
50Hz or 60Hz power, but turn at differnet speeds. You can use a
transfoemr to convert the voltage, but the speed is more of a problem.
The official fix is a different motor pulley. Getting one is aproblem. Of
coruse it's not hard to trun one if you haev a reasoanble workshop, but
rather hander if ytou ton't.
Mind you, in your case I suspect you could fidle the software decoding
routines to hadle the 'wrong' data rate. But it would be better to get a
drive runnig at the accepted speed so your routines were of use to others.
-tony
4:19 p.m.
On 01/03/11 19:58, Tony Duell wrote:
AFAIK, SA801s have one PCB which includes the
read/write chain and
stepepr controlelr, etc. There is no spindle motor controller, of course.
Indeed. The one I saw had the wires hacked off at various points (!) and
the PCB was completely gone. Something like that is worth scrap value at
best...
I'd better expand on that last part becuase it may
affect you buying a
drive second-hand. Msot, (but not all) 8" drives have cpacitor-run AC
spindle motors. Their speed is therefor set by the mains frequency.
As you would expect with AC motors.
I ahve seen both 15V and 230V motors in SA800s. Both
will run off either
50Hz or 60Hz power, but turn at differnet speeds. You can use a
transfoemr to convert the voltage, but the speed is more of a problem.
I assume you meant "115V and 230V motors", because I've seen the SA800
spec sheet, and IIRC it doesn't mention a 15V motor. The 115V boxen are
usually 60Hz, the 230s are usually 50Hz.
This, of course, means precisely nothing if you've got a spare mains
transformer, a sine wave oscillator and a power amplifier. DIY mains
inverter anyone? :)
The official fix is a different motor pulley. Getting
one is aproblem. Of
coruse it's not hard to trun one if you haev a reasoanble workshop, but
rather hander if ytou ton't.
And the cheat is -- as I've said -- to make a homebrew sine or
modified-sine inverter. An even better way is to find a drive with a
DC-drive motor. For instance, the NEC FD1165 takes 24V and 5V in.
Direct-drive spindle motor with integrated (read: big and heavy)
flywheel and an optical-encoder speed controller. Very spiffy. It's
still a brushed motor though, and I'm hoping the brushes are in decent
nick (I'm betting they won't be easy to replace!)
I fear tracking down a 6-pin "Berg" power connector might be...
"interesting". The 4-pin (PC 3.5 FDD power connector) variant is widely
available, but the AMP part number I have for the 6-pin is showing as
"discontinued"... Urrgh...
--
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/
5:01 p.m.
Hi
You should look for double sided, although the 801 will work for most
M2FM as they're mostly single sided.
Dwight
Date: Wed, 2 Mar 2011 00:19:22 +0000
From: classiccmp at philpem.me.uk
To:
Subject: Re: WTD: 8-inch floppy drive
On 01/03/11 19:58, Tony Duell wrote:
---snip---
AFAIK, SA801s have one PCB which includes the
read/write chain and
stepepr controlelr, etc. There is no spindle motor controller, of course.
Indeed. The one I saw had the wires hacked off at various points (!) and
the PCB was completely gone. Something like that is worth scrap value at
best...
5:35 p.m.
Tony Duell wrote:
AFAIK, SA801s have one PCB which includes the
read/write chain and
stepepr controlelr, etc. There is no spindle motor controller, of
course.
Philip Pemberton wrote:
Indeed. The one I saw had the wires hacked off at
various points (!)
and the PCB was completely gone. Something like that is worth scrap
value at best...
Tony wasn't saying that the spindle motor controller had been removed.
He was pointing out that such a drive by design has no spindle motor
controller, since it uses an AC motor. If you spend time looking for an
SA801 with an intact spindle motor controller, you'll be looking for a
very long time.
5:47 p.m.
On 02/03/11 01:35, Eric Smith wrote:
Tony wasn't saying that the spindle motor
controller had been removed.
He was pointing out that such a drive by design has no spindle motor
controller, since it uses an AC motor. If you spend time looking for an
SA801 with an intact spindle motor controller, you'll be looking for a
very long time.
I'm aware of that. What I was trying to say was "it was missing the
board which controls the heads and head stepper".
Evidently I need to look into disabling the Send button in my mail
client after midnight...
--
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/
2 Mar
2 Mar
11:14 a.m.
controller, since it uses an AC motor. If you spend
time looking for an
SA801 with an intact spindle motor controller, you'll be looking for a
very long time.
I have this crazy idea to make a crystal-controllerd oscillator to drive the
spindle motor (much on the lines that Philip (?) suggested, a pseudo-sine
wave oscillator driving a power amplifier and step-up transformer) just
so I can say I have an SA801 with a spindle motor controller :-)
-tony
4:52 a.m.
On Wed, 2 Mar 2011, Philip Pemberton wrote:
I fear tracking down a 6-pin "Berg" power
connector might be...
"interesting". The 4-pin (PC 3.5 FDD power connector) variant is widely
available, but the AMP part number I have for the 6-pin is showing as
"discontinued"... Urrgh...
Yes, but for a man of your considerable talents that's not a big deal.
Just pigtail another connector from the pins on the Berg :-).
--
11:11 a.m.
On 01/03/11 19:58, Tony Duell wrote:
IIRC, the connectors to the PCB on the SA801 are a SIL plug and socket
for the head wires (like on many full-height 5.25" drives) and a card
edge connector for everything else on the front edge of the PCB. To
remove individual bits, like the index sensor, you were supplsoed to
remvoe the cotnacts fdrom the femal part of this edge connector with a
special tool.
Quite why anyone would hack the connector off unless they though the goc
plating wasworth a lot, I don;t know....
Anyway, such a drive might be useful for a spare head/stepper assembly,
but I woun't pay much for it....
AFAIK, SA801s have one PCB which includes the
read/write chain and
stepepr controlelr, etc. There is no spindle motor controller, of course.
Indeed. The one I saw had the wires hacked off at various points (!) and
the PCB was completely gone. Something like that is worth scrap value at
best... I'd better expand on that last part becuase
it may affect you buying a
drive second-hand. Msot, (but not all) 8" drives have cpacitor-run AC
spindle motors. Their speed is therefor set by the mains frequency.
As you would expect with AC motors. I ahve seen both 15V and 230V motors in SA800s.
Both will run off either
50Hz or 60Hz power, but turn at differnet speeds. You can use a
transfoemr to convert the voltage, but the speed is more of a problem.
I assume you meant "115V and 230V motors", because I've seen the SA800
spec sheet, and IIRC it doesn't mention a 15V
motor. The 115V boxen are
usually 60Hz, the 230s are usually 50Hz.
Not always... I have never seen a 230V 60Hz one, but I have seen plenty
of 115V 50Hz ones. They are commonly used in the UK, the motor is run
from the tapped primary of the mains transformer that
ppowers the rrest
of the electroncis, acting as an autotransfornmer. I have
certainly got
some in my machines.
This, of course, means precisely nothing if you've got a spare mains
transformer, a sine wave oscillator and a power amplifier. DIY mains
inverter anyone? :)
Sure...
The official fix is a different motor pulley.
Getting one is aproblem. Of
coruse it's not hard to trun one if you haev a reasoanble workshop, but
rather hander if ytou ton't.
And the cheat is -- as I've said -- to make a homebrew sine or
modified-sine inverter. An even better way is to find a drive with a
DC-drive motor. For instance, the NEC FD1165 takes 24V and 5V in. Direct-drive spindle motor with integrated (read: big
and heavy)
flywheel and an optical-encoder speed controller. Very spiffy. It's
still a brushed motor though, and I'm hoping the brushes are in decent
nick (I'm betting they won't be easy to replace!)
But probably easier to find than a custom chip for some obscure logic
board :-)
Do you have such a drive?
I fear tracking down a 6-pin "Berg" power connector might be...
"interesting". The 4-pin (PC 3.5 FDD power connector) variant is widely
Do you mean 3.5" here?
available, but the AMP part number I have for the
6-pin is showing as
"discontinued"... Urrgh...
The normal 8" drive power connector has 2 rows of 3 pins. The
cable-mounting housing is roughly H-shaped at the business end with the
corssbar offset so it will only fit one way round.
The socket contcats are easy to get (I am pretty sure Farnell do
something that will fit). You can cover individualy ones with heat-shrink
and putsh themonto the right pins of the connector. Just make sure they
are the right pins :-)
For I have a kludge, and a good kludge too :-)
-tony
1 Mar
1 Mar
2:34 p.m.
I have a Shugart 801 FDD I've been trying to sell. Yours
for reasonable offer, plus shipping. Condition: Working when
removed from my external box I built for my LSI-11. The motor is 115
volts, 60 cycles. Number of boards/components missing: None.
At 06:20 AM 3/1/2011, you wrote:
Hi guys,
I'm trying to track down an 8-inch floppy drive to read an Intel MDS
M2FM disc I've been sent for adding to the DiscFerret decoder
engine. Specifically: it's an ISIS boot floppy, in SS/DD format.
Does anyone have a spare 8in drive gathering dust in a corner
somewhere? Based on the prices on Greed-Bay, I get the impression
most of the sellers have been engaging in some form of abuse of
illicit substances.... I mean, seriously, $700 for a Shugart 801,
"untested" (which would seem to be a synonym for "I know it's broken
but I sure as hell won't admit it!") and missing the head-amp /
motor control PCB?
Thanks,
--
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/
2:50 p.m.
IIRC the tandon TM-848-2 drives use 24VDC motors... I always liked them
better than the shugart drives.
2 Mar
2 Mar
10:52 a.m.
IIRC the tandon TM-848-2 drives use 24VDC motors... I always liked them
better than the shugart drives.
I did say 'Most' 8" drives have AC mains motors, not 'all' :-).
24V DC motors with some kind of electrronic speed control was an option
on some other drives too. I have a pair of drives made by a company
called 'Elcomatic' nad according to the service manual, a 24V DC motor
was an option on those. Mine have 240V 50Hz motors though.
One other nice featuroe of these drives is a slotted optoswtich near the
head carrarriage that changes state at cylinder 43. This is used (I think
it's a jumper-selected option) to reduce the write current, so you don't
need to provide the TG43 signal from the controller. Very handy if you're
using them with a PC/AT controller ;-)
-tony
1 Mar
1 Mar
2:35 p.m.
Hello,
On Tue, Mar 1, 2011 at 1:20 PM, Philip Pemberton
<classiccmp at philpem.me.uk> wrote:
Hi guys,
I'm trying to track down an 8-inch floppy drive to read an Intel MDS M2FM
disc I've been sent for adding to the DiscFerret decoder engine.
Specifically: it's an ISIS boot floppy, in SS/DD format.
Interesting. I have in my possession, the following two floppies (both
are 8 inch):
1 x ELAB MDS-Link v. 4.5, SINTRAN part, format: SINTRAN III
1 x ELAB MDS-Link v. 4.6, INTEL MDS part, format: Intel ISIS-II DD
(SINTRAN III is / was the operating system for Norsk Data mini machines).
I also have a working ND-Satellite / 9 machine, complete with a
(working) 8 inch floppy drive.
This will read the SINTRAN III floppy fine, but I don't know if it can
read the ISIS-II DD format floppy, or if
I have the software required to do so.
Does anyone have a spare 8in drive gathering dust in a
corner somewhere?
Sorry, I don't have a spare 8 inch floppy drive.
--
Regards,
Torfinn Ingolfsen,
Norway
6:24 p.m.
On Tue, 1 Mar 2011, Philip Pemberton wrote:
Hi guys,
I'm trying to track down an 8-inch floppy drive to read an Intel MDS M2FM
disc I've been sent for adding to the DiscFerret decoder engine.
Specifically: it's an ISIS boot floppy, in SS/DD format.
Does anyone have a spare 8in drive gathering dust in a corner somewhere?
Based on the prices on Greed-Bay, I get the impression most of the sellers
have been engaging in some form of abuse of illicit substances.... I mean,
seriously, $700 for a Shugart 801, "untested" (which would seem to be a
synonym for "I know it's broken but I sure as hell won't admit it!")
and
missing the head-amp / motor control PCB?
Keep an eagle-eye on eBay. In the past few years I've picked up a number
of them, including three brand-new 1/2-ht Panasonic DC units. Not
everyone picks usurious price-points.
They do come along now and then.
--
5044
days inactive
5045
days old
13 comments
8 participants
participants (8)
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a50mhzham＠gmail.com -
ard＠p850ug1.demon.co.uk -
classiccmp＠philpem.me.uk -
dkelvey＠hotmail.com -
eric＠brouhaha.com -
geoffr＠zipcon.net -
snhirsch＠gmail.com -
tingox＠gmail.com